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* [PATCH v13 7/8] Row pattern recognition patch (tests).
@ 2024-01-22 09:45 Tatsuo Ishii <ishii@postgresql.org>
0 siblings, 0 replies; 656+ messages in thread
From: Tatsuo Ishii @ 2024-01-22 09:45 UTC (permalink / raw)
---
src/test/regress/expected/rpr.out | 821 +++++++++++++++++++++++++++++
src/test/regress/parallel_schedule | 2 +-
src/test/regress/sql/rpr.sql | 392 ++++++++++++++
3 files changed, 1214 insertions(+), 1 deletion(-)
create mode 100644 src/test/regress/expected/rpr.out
create mode 100644 src/test/regress/sql/rpr.sql
diff --git a/src/test/regress/expected/rpr.out b/src/test/regress/expected/rpr.out
new file mode 100644
index 0000000000..e8998ebf45
--- /dev/null
+++ b/src/test/regress/expected/rpr.out
@@ -0,0 +1,821 @@
+--
+-- Test for row pattern definition clause
+--
+CREATE TEMP TABLE stock (
+ company TEXT,
+ tdate DATE,
+ price INTEGER
+);
+INSERT INTO stock VALUES ('company1', '2023-07-01', 100);
+INSERT INTO stock VALUES ('company1', '2023-07-02', 200);
+INSERT INTO stock VALUES ('company1', '2023-07-03', 150);
+INSERT INTO stock VALUES ('company1', '2023-07-04', 140);
+INSERT INTO stock VALUES ('company1', '2023-07-05', 150);
+INSERT INTO stock VALUES ('company1', '2023-07-06', 90);
+INSERT INTO stock VALUES ('company1', '2023-07-07', 110);
+INSERT INTO stock VALUES ('company1', '2023-07-08', 130);
+INSERT INTO stock VALUES ('company1', '2023-07-09', 120);
+INSERT INTO stock VALUES ('company1', '2023-07-10', 130);
+INSERT INTO stock VALUES ('company2', '2023-07-01', 50);
+INSERT INTO stock VALUES ('company2', '2023-07-02', 2000);
+INSERT INTO stock VALUES ('company2', '2023-07-03', 1500);
+INSERT INTO stock VALUES ('company2', '2023-07-04', 1400);
+INSERT INTO stock VALUES ('company2', '2023-07-05', 1500);
+INSERT INTO stock VALUES ('company2', '2023-07-06', 60);
+INSERT INTO stock VALUES ('company2', '2023-07-07', 1100);
+INSERT INTO stock VALUES ('company2', '2023-07-08', 1300);
+INSERT INTO stock VALUES ('company2', '2023-07-09', 1200);
+INSERT INTO stock VALUES ('company2', '2023-07-10', 1300);
+SELECT * FROM stock;
+ company | tdate | price
+----------+------------+-------
+ company1 | 07-01-2023 | 100
+ company1 | 07-02-2023 | 200
+ company1 | 07-03-2023 | 150
+ company1 | 07-04-2023 | 140
+ company1 | 07-05-2023 | 150
+ company1 | 07-06-2023 | 90
+ company1 | 07-07-2023 | 110
+ company1 | 07-08-2023 | 130
+ company1 | 07-09-2023 | 120
+ company1 | 07-10-2023 | 130
+ company2 | 07-01-2023 | 50
+ company2 | 07-02-2023 | 2000
+ company2 | 07-03-2023 | 1500
+ company2 | 07-04-2023 | 1400
+ company2 | 07-05-2023 | 1500
+ company2 | 07-06-2023 | 60
+ company2 | 07-07-2023 | 1100
+ company2 | 07-08-2023 | 1300
+ company2 | 07-09-2023 | 1200
+ company2 | 07-10-2023 | 1300
+(20 rows)
+
+-- basic test using PREV
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w,
+ nth_value(tdate, 2) OVER w AS nth_second
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ company | tdate | price | first_value | last_value | nth_second
+----------+------------+-------+-------------+------------+------------
+ company1 | 07-01-2023 | 100 | 100 | 140 | 07-02-2023
+ company1 | 07-02-2023 | 200 | | |
+ company1 | 07-03-2023 | 150 | | |
+ company1 | 07-04-2023 | 140 | | |
+ company1 | 07-05-2023 | 150 | | |
+ company1 | 07-06-2023 | 90 | 90 | 120 | 07-07-2023
+ company1 | 07-07-2023 | 110 | | |
+ company1 | 07-08-2023 | 130 | | |
+ company1 | 07-09-2023 | 120 | | |
+ company1 | 07-10-2023 | 130 | | |
+ company2 | 07-01-2023 | 50 | 50 | 1400 | 07-02-2023
+ company2 | 07-02-2023 | 2000 | | |
+ company2 | 07-03-2023 | 1500 | | |
+ company2 | 07-04-2023 | 1400 | | |
+ company2 | 07-05-2023 | 1500 | | |
+ company2 | 07-06-2023 | 60 | 60 | 1200 | 07-07-2023
+ company2 | 07-07-2023 | 1100 | | |
+ company2 | 07-08-2023 | 1300 | | |
+ company2 | 07-09-2023 | 1200 | | |
+ company2 | 07-10-2023 | 1300 | | |
+(20 rows)
+
+-- basic test using PREV. UP appears twice
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w,
+ nth_value(tdate, 2) OVER w AS nth_second
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+ UP+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ company | tdate | price | first_value | last_value | nth_second
+----------+------------+-------+-------------+------------+------------
+ company1 | 07-01-2023 | 100 | 100 | 150 | 07-02-2023
+ company1 | 07-02-2023 | 200 | | |
+ company1 | 07-03-2023 | 150 | | |
+ company1 | 07-04-2023 | 140 | | |
+ company1 | 07-05-2023 | 150 | | |
+ company1 | 07-06-2023 | 90 | 90 | 130 | 07-07-2023
+ company1 | 07-07-2023 | 110 | | |
+ company1 | 07-08-2023 | 130 | | |
+ company1 | 07-09-2023 | 120 | | |
+ company1 | 07-10-2023 | 130 | | |
+ company2 | 07-01-2023 | 50 | 50 | 1500 | 07-02-2023
+ company2 | 07-02-2023 | 2000 | | |
+ company2 | 07-03-2023 | 1500 | | |
+ company2 | 07-04-2023 | 1400 | | |
+ company2 | 07-05-2023 | 1500 | | |
+ company2 | 07-06-2023 | 60 | 60 | 1300 | 07-07-2023
+ company2 | 07-07-2023 | 1100 | | |
+ company2 | 07-08-2023 | 1300 | | |
+ company2 | 07-09-2023 | 1200 | | |
+ company2 | 07-10-2023 | 1300 | | |
+(20 rows)
+
+-- basic test using PREV. Use '*'
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w,
+ nth_value(tdate, 2) OVER w AS nth_second
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP* DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ company | tdate | price | first_value | last_value | nth_second
+----------+------------+-------+-------------+------------+------------
+ company1 | 07-01-2023 | 100 | 100 | 140 | 07-02-2023
+ company1 | 07-02-2023 | 200 | | |
+ company1 | 07-03-2023 | 150 | | |
+ company1 | 07-04-2023 | 140 | | |
+ company1 | 07-05-2023 | 150 | 150 | 90 | 07-06-2023
+ company1 | 07-06-2023 | 90 | | |
+ company1 | 07-07-2023 | 110 | 110 | 120 | 07-08-2023
+ company1 | 07-08-2023 | 130 | | |
+ company1 | 07-09-2023 | 120 | | |
+ company1 | 07-10-2023 | 130 | | |
+ company2 | 07-01-2023 | 50 | 50 | 1400 | 07-02-2023
+ company2 | 07-02-2023 | 2000 | | |
+ company2 | 07-03-2023 | 1500 | | |
+ company2 | 07-04-2023 | 1400 | | |
+ company2 | 07-05-2023 | 1500 | 1500 | 60 | 07-06-2023
+ company2 | 07-06-2023 | 60 | | |
+ company2 | 07-07-2023 | 1100 | 1100 | 1200 | 07-08-2023
+ company2 | 07-08-2023 | 1300 | | |
+ company2 | 07-09-2023 | 1200 | | |
+ company2 | 07-10-2023 | 1300 | | |
+(20 rows)
+
+-- basic test with none greedy pattern
+SELECT company, tdate, price, count(*) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (A A A)
+ DEFINE
+ A AS price >= 140 AND price <= 150
+);
+ company | tdate | price | count
+----------+------------+-------+-------
+ company1 | 07-01-2023 | 100 | 0
+ company1 | 07-02-2023 | 200 | 0
+ company1 | 07-03-2023 | 150 | 3
+ company1 | 07-04-2023 | 140 |
+ company1 | 07-05-2023 | 150 |
+ company1 | 07-06-2023 | 90 | 0
+ company1 | 07-07-2023 | 110 | 0
+ company1 | 07-08-2023 | 130 | 0
+ company1 | 07-09-2023 | 120 | 0
+ company1 | 07-10-2023 | 130 | 0
+ company2 | 07-01-2023 | 50 | 0
+ company2 | 07-02-2023 | 2000 | 0
+ company2 | 07-03-2023 | 1500 | 0
+ company2 | 07-04-2023 | 1400 | 0
+ company2 | 07-05-2023 | 1500 | 0
+ company2 | 07-06-2023 | 60 | 0
+ company2 | 07-07-2023 | 1100 | 0
+ company2 | 07-08-2023 | 1300 | 0
+ company2 | 07-09-2023 | 1200 | 0
+ company2 | 07-10-2023 | 1300 | 0
+(20 rows)
+
+-- last_value() should remain consistent
+SELECT company, tdate, price, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ company | tdate | price | last_value
+----------+------------+-------+------------
+ company1 | 07-01-2023 | 100 | 140
+ company1 | 07-02-2023 | 200 |
+ company1 | 07-03-2023 | 150 |
+ company1 | 07-04-2023 | 140 |
+ company1 | 07-05-2023 | 150 |
+ company1 | 07-06-2023 | 90 | 120
+ company1 | 07-07-2023 | 110 |
+ company1 | 07-08-2023 | 130 |
+ company1 | 07-09-2023 | 120 |
+ company1 | 07-10-2023 | 130 |
+ company2 | 07-01-2023 | 50 | 1400
+ company2 | 07-02-2023 | 2000 |
+ company2 | 07-03-2023 | 1500 |
+ company2 | 07-04-2023 | 1400 |
+ company2 | 07-05-2023 | 1500 |
+ company2 | 07-06-2023 | 60 | 1200
+ company2 | 07-07-2023 | 1100 |
+ company2 | 07-08-2023 | 1300 |
+ company2 | 07-09-2023 | 1200 |
+ company2 | 07-10-2023 | 1300 |
+(20 rows)
+
+-- omit "START" in DEFINE but it is ok because "START AS TRUE" is
+-- implicitly defined. per spec.
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w,
+ nth_value(tdate, 2) OVER w AS nth_second
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ company | tdate | price | first_value | last_value | nth_second
+----------+------------+-------+-------------+------------+------------
+ company1 | 07-01-2023 | 100 | 100 | 140 | 07-02-2023
+ company1 | 07-02-2023 | 200 | | |
+ company1 | 07-03-2023 | 150 | | |
+ company1 | 07-04-2023 | 140 | | |
+ company1 | 07-05-2023 | 150 | | |
+ company1 | 07-06-2023 | 90 | 90 | 120 | 07-07-2023
+ company1 | 07-07-2023 | 110 | | |
+ company1 | 07-08-2023 | 130 | | |
+ company1 | 07-09-2023 | 120 | | |
+ company1 | 07-10-2023 | 130 | | |
+ company2 | 07-01-2023 | 50 | 50 | 1400 | 07-02-2023
+ company2 | 07-02-2023 | 2000 | | |
+ company2 | 07-03-2023 | 1500 | | |
+ company2 | 07-04-2023 | 1400 | | |
+ company2 | 07-05-2023 | 1500 | | |
+ company2 | 07-06-2023 | 60 | 60 | 1200 | 07-07-2023
+ company2 | 07-07-2023 | 1100 | | |
+ company2 | 07-08-2023 | 1300 | | |
+ company2 | 07-09-2023 | 1200 | | |
+ company2 | 07-10-2023 | 1300 | | |
+(20 rows)
+
+-- the first row start with less than or equal to 100
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ company | tdate | price | first_value | last_value
+----------+------------+-------+-------------+------------
+ company1 | 07-01-2023 | 100 | 100 | 140
+ company1 | 07-02-2023 | 200 | |
+ company1 | 07-03-2023 | 150 | |
+ company1 | 07-04-2023 | 140 | |
+ company1 | 07-05-2023 | 150 | |
+ company1 | 07-06-2023 | 90 | 90 | 120
+ company1 | 07-07-2023 | 110 | |
+ company1 | 07-08-2023 | 130 | |
+ company1 | 07-09-2023 | 120 | |
+ company1 | 07-10-2023 | 130 | |
+ company2 | 07-01-2023 | 50 | 50 | 1400
+ company2 | 07-02-2023 | 2000 | |
+ company2 | 07-03-2023 | 1500 | |
+ company2 | 07-04-2023 | 1400 | |
+ company2 | 07-05-2023 | 1500 | |
+ company2 | 07-06-2023 | 60 | 60 | 1200
+ company2 | 07-07-2023 | 1100 | |
+ company2 | 07-08-2023 | 1300 | |
+ company2 | 07-09-2023 | 1200 | |
+ company2 | 07-10-2023 | 1300 | |
+(20 rows)
+
+-- second row raises 120%
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price) * 1.2,
+ DOWN AS price < PREV(price)
+);
+ company | tdate | price | first_value | last_value
+----------+------------+-------+-------------+------------
+ company1 | 07-01-2023 | 100 | 100 | 140
+ company1 | 07-02-2023 | 200 | |
+ company1 | 07-03-2023 | 150 | |
+ company1 | 07-04-2023 | 140 | |
+ company1 | 07-05-2023 | 150 | |
+ company1 | 07-06-2023 | 90 | |
+ company1 | 07-07-2023 | 110 | |
+ company1 | 07-08-2023 | 130 | |
+ company1 | 07-09-2023 | 120 | |
+ company1 | 07-10-2023 | 130 | |
+ company2 | 07-01-2023 | 50 | 50 | 1400
+ company2 | 07-02-2023 | 2000 | |
+ company2 | 07-03-2023 | 1500 | |
+ company2 | 07-04-2023 | 1400 | |
+ company2 | 07-05-2023 | 1500 | |
+ company2 | 07-06-2023 | 60 | |
+ company2 | 07-07-2023 | 1100 | |
+ company2 | 07-08-2023 | 1300 | |
+ company2 | 07-09-2023 | 1200 | |
+ company2 | 07-10-2023 | 1300 | |
+(20 rows)
+
+-- using NEXT
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UPDOWN)
+ DEFINE
+ START AS TRUE,
+ UPDOWN AS price > PREV(price) AND price > NEXT(price)
+);
+ company | tdate | price | first_value | last_value
+----------+------------+-------+-------------+------------
+ company1 | 07-01-2023 | 100 | 100 | 200
+ company1 | 07-02-2023 | 200 | |
+ company1 | 07-03-2023 | 150 | |
+ company1 | 07-04-2023 | 140 | 140 | 150
+ company1 | 07-05-2023 | 150 | |
+ company1 | 07-06-2023 | 90 | |
+ company1 | 07-07-2023 | 110 | 110 | 130
+ company1 | 07-08-2023 | 130 | |
+ company1 | 07-09-2023 | 120 | |
+ company1 | 07-10-2023 | 130 | |
+ company2 | 07-01-2023 | 50 | 50 | 2000
+ company2 | 07-02-2023 | 2000 | |
+ company2 | 07-03-2023 | 1500 | |
+ company2 | 07-04-2023 | 1400 | 1400 | 1500
+ company2 | 07-05-2023 | 1500 | |
+ company2 | 07-06-2023 | 60 | |
+ company2 | 07-07-2023 | 1100 | 1100 | 1300
+ company2 | 07-08-2023 | 1300 | |
+ company2 | 07-09-2023 | 1200 | |
+ company2 | 07-10-2023 | 1300 | |
+(20 rows)
+
+-- using AFTER MATCH SKIP TO NEXT ROW
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP TO NEXT ROW
+ INITIAL
+ PATTERN (START UPDOWN)
+ DEFINE
+ START AS TRUE,
+ UPDOWN AS price > PREV(price) AND price > NEXT(price)
+);
+ company | tdate | price | first_value | last_value
+----------+------------+-------+-------------+------------
+ company1 | 07-01-2023 | 100 | 100 | 200
+ company1 | 07-02-2023 | 200 | |
+ company1 | 07-03-2023 | 150 | |
+ company1 | 07-04-2023 | 140 | 140 | 150
+ company1 | 07-05-2023 | 150 | |
+ company1 | 07-06-2023 | 90 | |
+ company1 | 07-07-2023 | 110 | 110 | 130
+ company1 | 07-08-2023 | 130 | |
+ company1 | 07-09-2023 | 120 | |
+ company1 | 07-10-2023 | 130 | |
+ company2 | 07-01-2023 | 50 | 50 | 2000
+ company2 | 07-02-2023 | 2000 | |
+ company2 | 07-03-2023 | 1500 | |
+ company2 | 07-04-2023 | 1400 | 1400 | 1500
+ company2 | 07-05-2023 | 1500 | |
+ company2 | 07-06-2023 | 60 | |
+ company2 | 07-07-2023 | 1100 | 1100 | 1300
+ company2 | 07-08-2023 | 1300 | |
+ company2 | 07-09-2023 | 1200 | |
+ company2 | 07-10-2023 | 1300 | |
+(20 rows)
+
+-- match everything
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (A+)
+ DEFINE
+ A AS TRUE
+);
+ company | tdate | price | first_value | last_value
+----------+------------+-------+-------------+------------
+ company1 | 07-01-2023 | 100 | 100 | 130
+ company1 | 07-02-2023 | 200 | |
+ company1 | 07-03-2023 | 150 | |
+ company1 | 07-04-2023 | 140 | |
+ company1 | 07-05-2023 | 150 | |
+ company1 | 07-06-2023 | 90 | |
+ company1 | 07-07-2023 | 110 | |
+ company1 | 07-08-2023 | 130 | |
+ company1 | 07-09-2023 | 120 | |
+ company1 | 07-10-2023 | 130 | |
+ company2 | 07-01-2023 | 50 | 50 | 1300
+ company2 | 07-02-2023 | 2000 | |
+ company2 | 07-03-2023 | 1500 | |
+ company2 | 07-04-2023 | 1400 | |
+ company2 | 07-05-2023 | 1500 | |
+ company2 | 07-06-2023 | 60 | |
+ company2 | 07-07-2023 | 1100 | |
+ company2 | 07-08-2023 | 1300 | |
+ company2 | 07-09-2023 | 1200 | |
+ company2 | 07-10-2023 | 1300 | |
+(20 rows)
+
+-- backtracking with reclassification of rows
+-- using AFTER MATCH SKIP PAST LAST ROW
+SELECT company, tdate, price, first_value(tdate) OVER w, last_value(tdate) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (A+ B+)
+ DEFINE
+ A AS price > 100,
+ B AS price > 100
+);
+ company | tdate | price | first_value | last_value
+----------+------------+-------+-------------+------------
+ company1 | 07-01-2023 | 100 | |
+ company1 | 07-02-2023 | 200 | 07-02-2023 | 07-05-2023
+ company1 | 07-03-2023 | 150 | |
+ company1 | 07-04-2023 | 140 | |
+ company1 | 07-05-2023 | 150 | |
+ company1 | 07-06-2023 | 90 | |
+ company1 | 07-07-2023 | 110 | 07-07-2023 | 07-10-2023
+ company1 | 07-08-2023 | 130 | |
+ company1 | 07-09-2023 | 120 | |
+ company1 | 07-10-2023 | 130 | |
+ company2 | 07-01-2023 | 50 | |
+ company2 | 07-02-2023 | 2000 | 07-02-2023 | 07-05-2023
+ company2 | 07-03-2023 | 1500 | |
+ company2 | 07-04-2023 | 1400 | |
+ company2 | 07-05-2023 | 1500 | |
+ company2 | 07-06-2023 | 60 | |
+ company2 | 07-07-2023 | 1100 | 07-07-2023 | 07-10-2023
+ company2 | 07-08-2023 | 1300 | |
+ company2 | 07-09-2023 | 1200 | |
+ company2 | 07-10-2023 | 1300 | |
+(20 rows)
+
+-- backtracking with reclassification of rows
+-- using AFTER MATCH SKIP TO NEXT ROW
+SELECT company, tdate, price, first_value(tdate) OVER w, last_value(tdate) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP TO NEXT ROW
+ INITIAL
+ PATTERN (A+ B+)
+ DEFINE
+ A AS price > 100,
+ B AS price > 100
+);
+ company | tdate | price | first_value | last_value
+----------+------------+-------+-------------+------------
+ company1 | 07-01-2023 | 100 | |
+ company1 | 07-02-2023 | 200 | 07-02-2023 | 07-05-2023
+ company1 | 07-03-2023 | 150 | 07-03-2023 | 07-05-2023
+ company1 | 07-04-2023 | 140 | 07-04-2023 | 07-05-2023
+ company1 | 07-05-2023 | 150 | |
+ company1 | 07-06-2023 | 90 | |
+ company1 | 07-07-2023 | 110 | 07-07-2023 | 07-10-2023
+ company1 | 07-08-2023 | 130 | 07-08-2023 | 07-10-2023
+ company1 | 07-09-2023 | 120 | 07-09-2023 | 07-10-2023
+ company1 | 07-10-2023 | 130 | |
+ company2 | 07-01-2023 | 50 | |
+ company2 | 07-02-2023 | 2000 | 07-02-2023 | 07-05-2023
+ company2 | 07-03-2023 | 1500 | 07-03-2023 | 07-05-2023
+ company2 | 07-04-2023 | 1400 | 07-04-2023 | 07-05-2023
+ company2 | 07-05-2023 | 1500 | |
+ company2 | 07-06-2023 | 60 | |
+ company2 | 07-07-2023 | 1100 | 07-07-2023 | 07-10-2023
+ company2 | 07-08-2023 | 1300 | 07-08-2023 | 07-10-2023
+ company2 | 07-09-2023 | 1200 | 07-09-2023 | 07-10-2023
+ company2 | 07-10-2023 | 1300 | |
+(20 rows)
+
+-- ROWS BETWEEN CURRENT ROW AND offset FOLLOWING
+SELECT company, tdate, price, first_value(tdate) OVER w, last_value(tdate) OVER w,
+ count(*) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ company | tdate | price | first_value | last_value | count
+----------+------------+-------+-------------+------------+-------
+ company1 | 07-01-2023 | 100 | 07-01-2023 | 07-03-2023 | 3
+ company1 | 07-02-2023 | 200 | | |
+ company1 | 07-03-2023 | 150 | | |
+ company1 | 07-04-2023 | 140 | 07-04-2023 | 07-06-2023 | 3
+ company1 | 07-05-2023 | 150 | | |
+ company1 | 07-06-2023 | 90 | | |
+ company1 | 07-07-2023 | 110 | 07-07-2023 | 07-09-2023 | 3
+ company1 | 07-08-2023 | 130 | | |
+ company1 | 07-09-2023 | 120 | | |
+ company1 | 07-10-2023 | 130 | | | 0
+ company2 | 07-01-2023 | 50 | 07-01-2023 | 07-03-2023 | 3
+ company2 | 07-02-2023 | 2000 | | |
+ company2 | 07-03-2023 | 1500 | | |
+ company2 | 07-04-2023 | 1400 | 07-04-2023 | 07-06-2023 | 3
+ company2 | 07-05-2023 | 1500 | | |
+ company2 | 07-06-2023 | 60 | | |
+ company2 | 07-07-2023 | 1100 | 07-07-2023 | 07-09-2023 | 3
+ company2 | 07-08-2023 | 1300 | | |
+ company2 | 07-09-2023 | 1200 | | |
+ company2 | 07-10-2023 | 1300 | | | 0
+(20 rows)
+
+--
+-- Aggregates
+--
+-- using AFTER MATCH SKIP PAST LAST ROW
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ last_value(price) OVER w,
+ max(price) OVER w,
+ min(price) OVER w,
+ sum(price) OVER w,
+ avg(price) OVER w,
+ count(price) OVER w
+FROM stock
+WINDOW w AS (
+PARTITION BY company
+ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+AFTER MATCH SKIP PAST LAST ROW
+INITIAL
+PATTERN (START UP+ DOWN+)
+DEFINE
+START AS TRUE,
+UP AS price > PREV(price),
+DOWN AS price < PREV(price)
+);
+ company | tdate | price | first_value | last_value | max | min | sum | avg | count
+----------+------------+-------+-------------+------------+------+-----+------+-----------------------+-------
+ company1 | 07-01-2023 | 100 | 100 | 140 | 200 | 100 | 590 | 147.5000000000000000 | 4
+ company1 | 07-02-2023 | 200 | | | | | | |
+ company1 | 07-03-2023 | 150 | | | | | | |
+ company1 | 07-04-2023 | 140 | | | | | | |
+ company1 | 07-05-2023 | 150 | | | | | | | 0
+ company1 | 07-06-2023 | 90 | 90 | 120 | 130 | 90 | 450 | 112.5000000000000000 | 4
+ company1 | 07-07-2023 | 110 | | | | | | |
+ company1 | 07-08-2023 | 130 | | | | | | |
+ company1 | 07-09-2023 | 120 | | | | | | |
+ company1 | 07-10-2023 | 130 | | | | | | | 0
+ company2 | 07-01-2023 | 50 | 50 | 1400 | 2000 | 50 | 4950 | 1237.5000000000000000 | 4
+ company2 | 07-02-2023 | 2000 | | | | | | |
+ company2 | 07-03-2023 | 1500 | | | | | | |
+ company2 | 07-04-2023 | 1400 | | | | | | |
+ company2 | 07-05-2023 | 1500 | | | | | | | 0
+ company2 | 07-06-2023 | 60 | 60 | 1200 | 1300 | 60 | 3660 | 915.0000000000000000 | 4
+ company2 | 07-07-2023 | 1100 | | | | | | |
+ company2 | 07-08-2023 | 1300 | | | | | | |
+ company2 | 07-09-2023 | 1200 | | | | | | |
+ company2 | 07-10-2023 | 1300 | | | | | | | 0
+(20 rows)
+
+-- using AFTER MATCH SKIP TO NEXT ROW
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ last_value(price) OVER w,
+ max(price) OVER w,
+ min(price) OVER w,
+ sum(price) OVER w,
+ avg(price) OVER w,
+ count(price) OVER w
+FROM stock
+WINDOW w AS (
+PARTITION BY company
+ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+AFTER MATCH SKIP TO NEXT ROW
+INITIAL
+PATTERN (START UP+ DOWN+)
+DEFINE
+START AS TRUE,
+UP AS price > PREV(price),
+DOWN AS price < PREV(price)
+);
+ company | tdate | price | first_value | last_value | max | min | sum | avg | count
+----------+------------+-------+-------------+------------+------+------+------+-----------------------+-------
+ company1 | 07-01-2023 | 100 | 100 | 140 | 200 | 100 | 590 | 147.5000000000000000 | 4
+ company1 | 07-02-2023 | 200 | | | | | | | 0
+ company1 | 07-03-2023 | 150 | | | | | | | 0
+ company1 | 07-04-2023 | 140 | 140 | 90 | 150 | 90 | 380 | 126.6666666666666667 | 3
+ company1 | 07-05-2023 | 150 | | | | | | | 0
+ company1 | 07-06-2023 | 90 | 90 | 120 | 130 | 90 | 450 | 112.5000000000000000 | 4
+ company1 | 07-07-2023 | 110 | 110 | 120 | 130 | 110 | 360 | 120.0000000000000000 | 3
+ company1 | 07-08-2023 | 130 | | | | | | | 0
+ company1 | 07-09-2023 | 120 | | | | | | | 0
+ company1 | 07-10-2023 | 130 | | | | | | | 0
+ company2 | 07-01-2023 | 50 | 50 | 1400 | 2000 | 50 | 4950 | 1237.5000000000000000 | 4
+ company2 | 07-02-2023 | 2000 | | | | | | | 0
+ company2 | 07-03-2023 | 1500 | | | | | | | 0
+ company2 | 07-04-2023 | 1400 | 1400 | 60 | 1500 | 60 | 2960 | 986.6666666666666667 | 3
+ company2 | 07-05-2023 | 1500 | | | | | | | 0
+ company2 | 07-06-2023 | 60 | 60 | 1200 | 1300 | 60 | 3660 | 915.0000000000000000 | 4
+ company2 | 07-07-2023 | 1100 | 1100 | 1200 | 1300 | 1100 | 3600 | 1200.0000000000000000 | 3
+ company2 | 07-08-2023 | 1300 | | | | | | | 0
+ company2 | 07-09-2023 | 1200 | | | | | | | 0
+ company2 | 07-10-2023 | 1300 | | | | | | | 0
+(20 rows)
+
+-- JOIN case
+CREATE TEMP TABLE t1 (i int, v1 int);
+CREATE TEMP TABLE t2 (j int, v2 int);
+INSERT INTO t1 VALUES(1,10);
+INSERT INTO t1 VALUES(1,11);
+INSERT INTO t1 VALUES(1,12);
+INSERT INTO t2 VALUES(2,10);
+INSERT INTO t2 VALUES(2,11);
+INSERT INTO t2 VALUES(2,12);
+SELECT * FROM t1, t2 WHERE t1.v1 <= 11 AND t2.v2 <= 11;
+ i | v1 | j | v2
+---+----+---+----
+ 1 | 10 | 2 | 10
+ 1 | 10 | 2 | 11
+ 1 | 11 | 2 | 10
+ 1 | 11 | 2 | 11
+(4 rows)
+
+SELECT *, count(*) OVER w FROM t1, t2
+WINDOW w AS (
+ PARTITION BY t1.i
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (A)
+ DEFINE
+ A AS v1 <= 11 AND v2 <= 11
+);
+ i | v1 | j | v2 | count
+---+----+---+----+-------
+ 1 | 10 | 2 | 10 | 1
+ 1 | 10 | 2 | 11 | 1
+ 1 | 10 | 2 | 12 | 0
+ 1 | 11 | 2 | 10 | 1
+ 1 | 11 | 2 | 11 | 1
+ 1 | 11 | 2 | 12 | 0
+ 1 | 12 | 2 | 10 | 0
+ 1 | 12 | 2 | 11 | 0
+ 1 | 12 | 2 | 12 | 0
+(9 rows)
+
+-- WITH case
+WITH wstock AS (
+ SELECT * FROM stock WHERE tdate < '2023-07-08'
+)
+SELECT tdate, price,
+first_value(tdate) OVER w,
+count(*) OVER w
+ FROM wstock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ tdate | price | first_value | count
+------------+-------+-------------+-------
+ 07-01-2023 | 100 | 07-01-2023 | 4
+ 07-02-2023 | 200 | |
+ 07-03-2023 | 150 | |
+ 07-04-2023 | 140 | |
+ 07-05-2023 | 150 | | 0
+ 07-06-2023 | 90 | | 0
+ 07-07-2023 | 110 | | 0
+ 07-01-2023 | 50 | 07-01-2023 | 4
+ 07-02-2023 | 2000 | |
+ 07-03-2023 | 1500 | |
+ 07-04-2023 | 1400 | |
+ 07-05-2023 | 1500 | | 0
+ 07-06-2023 | 60 | | 0
+ 07-07-2023 | 1100 | | 0
+(14 rows)
+
+--
+-- Error cases
+--
+-- row pattern definition variable name must not appear more than once
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ ORDER BY tdate
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price),
+ UP AS price > PREV(price)
+);
+ERROR: syntax error at or near "ORDER"
+LINE 6: ORDER BY tdate
+ ^
+-- pattern variable name must appear in DEFINE
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+ END)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ERROR: syntax error at or near "END"
+LINE 8: PATTERN (START UP+ DOWN+ END)
+ ^
+-- FRAME must start at current row when row patttern recognition is used
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ERROR: FRAME must start at current row when row patttern recognition is used
+-- SEEK is not supported
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP TO NEXT ROW
+ SEEK
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+ERROR: SEEK is not supported
+LINE 8: SEEK
+ ^
+HINT: Use INITIAL.
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index f0987ff537..a6542f3dea 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -98,7 +98,7 @@ test: publication subscription
# Another group of parallel tests
# select_views depends on create_view
# ----------
-test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combocid tsearch tsdicts foreign_data window xmlmap functional_deps advisory_lock indirect_toast equivclass
+test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combocid tsearch tsdicts foreign_data window xmlmap functional_deps advisory_lock indirect_toast equivclass rpr
# ----------
# Another group of parallel tests (JSON related)
diff --git a/src/test/regress/sql/rpr.sql b/src/test/regress/sql/rpr.sql
new file mode 100644
index 0000000000..0a69cc0e11
--- /dev/null
+++ b/src/test/regress/sql/rpr.sql
@@ -0,0 +1,392 @@
+--
+-- Test for row pattern definition clause
+--
+
+CREATE TEMP TABLE stock (
+ company TEXT,
+ tdate DATE,
+ price INTEGER
+);
+INSERT INTO stock VALUES ('company1', '2023-07-01', 100);
+INSERT INTO stock VALUES ('company1', '2023-07-02', 200);
+INSERT INTO stock VALUES ('company1', '2023-07-03', 150);
+INSERT INTO stock VALUES ('company1', '2023-07-04', 140);
+INSERT INTO stock VALUES ('company1', '2023-07-05', 150);
+INSERT INTO stock VALUES ('company1', '2023-07-06', 90);
+INSERT INTO stock VALUES ('company1', '2023-07-07', 110);
+INSERT INTO stock VALUES ('company1', '2023-07-08', 130);
+INSERT INTO stock VALUES ('company1', '2023-07-09', 120);
+INSERT INTO stock VALUES ('company1', '2023-07-10', 130);
+INSERT INTO stock VALUES ('company2', '2023-07-01', 50);
+INSERT INTO stock VALUES ('company2', '2023-07-02', 2000);
+INSERT INTO stock VALUES ('company2', '2023-07-03', 1500);
+INSERT INTO stock VALUES ('company2', '2023-07-04', 1400);
+INSERT INTO stock VALUES ('company2', '2023-07-05', 1500);
+INSERT INTO stock VALUES ('company2', '2023-07-06', 60);
+INSERT INTO stock VALUES ('company2', '2023-07-07', 1100);
+INSERT INTO stock VALUES ('company2', '2023-07-08', 1300);
+INSERT INTO stock VALUES ('company2', '2023-07-09', 1200);
+INSERT INTO stock VALUES ('company2', '2023-07-10', 1300);
+
+SELECT * FROM stock;
+
+-- basic test using PREV
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w,
+ nth_value(tdate, 2) OVER w AS nth_second
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+
+-- basic test using PREV. UP appears twice
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w,
+ nth_value(tdate, 2) OVER w AS nth_second
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+ UP+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+
+-- basic test using PREV. Use '*'
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w,
+ nth_value(tdate, 2) OVER w AS nth_second
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP* DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+
+-- basic test with none greedy pattern
+SELECT company, tdate, price, count(*) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (A A A)
+ DEFINE
+ A AS price >= 140 AND price <= 150
+);
+
+-- last_value() should remain consistent
+SELECT company, tdate, price, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+
+-- omit "START" in DEFINE but it is ok because "START AS TRUE" is
+-- implicitly defined. per spec.
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w,
+ nth_value(tdate, 2) OVER w AS nth_second
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+
+-- the first row start with less than or equal to 100
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+
+-- second row raises 120%
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+ LOWPRICE AS price <= 100,
+ UP AS price > PREV(price) * 1.2,
+ DOWN AS price < PREV(price)
+);
+
+-- using NEXT
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UPDOWN)
+ DEFINE
+ START AS TRUE,
+ UPDOWN AS price > PREV(price) AND price > NEXT(price)
+);
+
+-- using AFTER MATCH SKIP TO NEXT ROW
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP TO NEXT ROW
+ INITIAL
+ PATTERN (START UPDOWN)
+ DEFINE
+ START AS TRUE,
+ UPDOWN AS price > PREV(price) AND price > NEXT(price)
+);
+
+-- match everything
+
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (A+)
+ DEFINE
+ A AS TRUE
+);
+
+-- backtracking with reclassification of rows
+-- using AFTER MATCH SKIP PAST LAST ROW
+SELECT company, tdate, price, first_value(tdate) OVER w, last_value(tdate) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (A+ B+)
+ DEFINE
+ A AS price > 100,
+ B AS price > 100
+);
+
+-- backtracking with reclassification of rows
+-- using AFTER MATCH SKIP TO NEXT ROW
+SELECT company, tdate, price, first_value(tdate) OVER w, last_value(tdate) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP TO NEXT ROW
+ INITIAL
+ PATTERN (A+ B+)
+ DEFINE
+ A AS price > 100,
+ B AS price > 100
+);
+
+-- ROWS BETWEEN CURRENT ROW AND offset FOLLOWING
+SELECT company, tdate, price, first_value(tdate) OVER w, last_value(tdate) OVER w,
+ count(*) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+
+--
+-- Aggregates
+--
+
+-- using AFTER MATCH SKIP PAST LAST ROW
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ last_value(price) OVER w,
+ max(price) OVER w,
+ min(price) OVER w,
+ sum(price) OVER w,
+ avg(price) OVER w,
+ count(price) OVER w
+FROM stock
+WINDOW w AS (
+PARTITION BY company
+ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+AFTER MATCH SKIP PAST LAST ROW
+INITIAL
+PATTERN (START UP+ DOWN+)
+DEFINE
+START AS TRUE,
+UP AS price > PREV(price),
+DOWN AS price < PREV(price)
+);
+
+-- using AFTER MATCH SKIP TO NEXT ROW
+SELECT company, tdate, price,
+ first_value(price) OVER w,
+ last_value(price) OVER w,
+ max(price) OVER w,
+ min(price) OVER w,
+ sum(price) OVER w,
+ avg(price) OVER w,
+ count(price) OVER w
+FROM stock
+WINDOW w AS (
+PARTITION BY company
+ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+AFTER MATCH SKIP TO NEXT ROW
+INITIAL
+PATTERN (START UP+ DOWN+)
+DEFINE
+START AS TRUE,
+UP AS price > PREV(price),
+DOWN AS price < PREV(price)
+);
+
+-- JOIN case
+CREATE TEMP TABLE t1 (i int, v1 int);
+CREATE TEMP TABLE t2 (j int, v2 int);
+INSERT INTO t1 VALUES(1,10);
+INSERT INTO t1 VALUES(1,11);
+INSERT INTO t1 VALUES(1,12);
+INSERT INTO t2 VALUES(2,10);
+INSERT INTO t2 VALUES(2,11);
+INSERT INTO t2 VALUES(2,12);
+
+SELECT * FROM t1, t2 WHERE t1.v1 <= 11 AND t2.v2 <= 11;
+
+SELECT *, count(*) OVER w FROM t1, t2
+WINDOW w AS (
+ PARTITION BY t1.i
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (A)
+ DEFINE
+ A AS v1 <= 11 AND v2 <= 11
+);
+
+-- WITH case
+WITH wstock AS (
+ SELECT * FROM stock WHERE tdate < '2023-07-08'
+)
+SELECT tdate, price,
+first_value(tdate) OVER w,
+count(*) OVER w
+ FROM wstock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+
+--
+-- Error cases
+--
+
+-- row pattern definition variable name must not appear more than once
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ ORDER BY tdate
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price),
+ UP AS price > PREV(price)
+);
+
+-- pattern variable name must appear in DEFINE
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+ END)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+
+-- FRAME must start at current row when row patttern recognition is used
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
+ INITIAL
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
+
+-- SEEK is not supported
+SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w
+ FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ORDER BY tdate
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP TO NEXT ROW
+ SEEK
+ PATTERN (START UP+ DOWN+)
+ DEFINE
+ START AS TRUE,
+ UP AS price > PREV(price),
+ DOWN AS price < PREV(price)
+);
--
2.25.1
----Next_Part(Mon_Jan_22_19_26_18_2024_011)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v13-0008-Allow-to-print-raw-parse-tree.patch"
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/akS/ldidWeqG1FWk%40bdtpg
---
src/backend/utils/activity/pgstat.c | 46 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 7 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..540db1ef115 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,14 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
- Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1338,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1361,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--cdkC2WBRrpXQO1hi--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 05:43 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 0 replies; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 05:43 UTC (permalink / raw)
If a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call
to pgstat_register_kind(). The SQL functions are still created, and
calling them invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would
dereference NULL and segfault.
Add runtime checks in all public-facing pgstat functions that accept a
PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
This affects any extension using the custom cumulative statistics API
introduced in PG18.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by:
Discussion:
---
src/backend/utils/activity/pgstat.c | 45 ++++++++++++++++++++---
src/backend/utils/activity/pgstat_shmem.c | 13 ++++++-
2 files changed, 52 insertions(+), 6 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index c4fa14f138f..5180201c4e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -885,8 +885,13 @@ pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* not needed atm, and doesn't make sense with the current signature */
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
/* reset the "single counter" */
pgstat_reset_entry(kind, dboid, objid, ts);
@@ -907,6 +912,11 @@ pgstat_reset_of_kind(PgStat_Kind kind)
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
TimestampTz ts = GetCurrentTimestamp();
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
if (kind_info->fixed_amount)
kind_info->reset_all_cb(ts);
else
@@ -967,6 +977,11 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *may_free)
void *stats_data;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* should be called from backends */
Assert(IsUnderPostmaster || !IsPostmasterEnvironment);
Assert(!kind_info->fixed_amount);
@@ -1088,8 +1103,15 @@ pgstat_get_stat_snapshot_timestamp(bool *have_snapshot)
bool
pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/* fixed-numbered stats always exist */
- if (pgstat_get_kind_info(kind)->fixed_amount)
+ if (kind_info->fixed_amount)
return true;
return pgstat_get_entry_ref(kind, dboid, objid, false, NULL) != NULL;
@@ -1104,8 +1126,15 @@ pgstat_have_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
void
pgstat_snapshot_fixed(PgStat_Kind kind)
{
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
Assert(pgstat_is_kind_valid(kind));
- Assert(pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(kind_info->fixed_amount);
if (force_stats_snapshot_clear)
pgstat_clear_snapshot();
@@ -1310,9 +1339,15 @@ PgStat_EntryRef *
pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *created_entry)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
/* need to be able to flush out */
- Assert(pgstat_get_kind_info(kind)->flush_pending_cb != NULL);
+ Assert(kind_info->flush_pending_cb != NULL);
if (unlikely(!pgStatPendingContext))
{
@@ -1327,7 +1362,7 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index 5ea3f1973f9..4e6a556af93 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -318,6 +318,11 @@ pgstat_init_entry(PgStat_Kind kind,
PgStatShared_Common *shheader;
const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
+
/*
* Initialize refcount to 1, marking it as valid / not dropped. The entry
* can't be freed before the initialization because it can't be found as
@@ -1127,8 +1132,14 @@ void
pgstat_reset_entry(PgStat_Kind kind, Oid dboid, uint64 objid, TimestampTz ts)
{
PgStat_EntryRef *entry_ref;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (unlikely(kind_info == NULL))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("statistics kind %u is not known or registered", kind)));
- Assert(!pgstat_get_kind_info(kind)->fixed_amount);
+ Assert(!kind_info->fixed_amount);
entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL);
if (!entry_ref || entry_ref->shared_entry->dropped)
--
2.34.1
--jlSGGOUQ0kGWBHE+--
^ permalink raw reply [nested|flat] 656+ messages in thread
* Prevent crash when calling pgstat functions with unregistered stats kind
@ 2026-07-01 07:19 Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
0 siblings, 1 reply; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-01 07:19 UTC (permalink / raw)
To: pgsql-hackers@lists.postgresql.org; +Cc: Michael Paquier <michael@paquier.xyz>
Hi hackers,
While reviewing [1], I got segfault(s) because I created a custom statistics
extension that I forgot to add to shared_preload_libraries. Then using one of
its function produced:
"
Core was generated by `postgres: postgres postgres [local] SELECT '.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 pgstat_init_entry (kind=kind@entry=24, shhashent=shhashent@entry=0x73f6c341a740) at pgstat_shmem.c:335
335 chunk = dsa_allocate_extended(pgStatLocal.dsa,
"
Indeed, if a custom statistics extension is loaded via CREATE EXTENSION without
being listed in shared_preload_libraries, its _PG_init() skips the call to
pgstat_register_kind(). The SQL functions are still created, and calling them
invokes pgstat functions with a kind that was never registered.
pgstat_get_kind_info() returns NULL in this case. The existing code only
checked this via Assert() in some paths, so non-assert builds would dereference
NULL and segfault.
The attached patch adds runtime checks in all public-facing pgstat functions that
accept a PgStat_Kind and dereference the returned kind info:
- pgstat_prep_pending_entry()
- pgstat_fetch_entry()
- pgstat_reset()
- pgstat_reset_of_kind()
- pgstat_have_entry()
- pgstat_snapshot_fixed()
- pgstat_init_entry()
- pgstat_reset_entry()
Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
the kind is not known or registered.
[1]: https://postgr.es/m/akSi2txzLZWQL31Q%40bdtpg
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 656+ messages in thread
* Re: Prevent crash when calling pgstat functions with unregistered stats kind
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
@ 2026-07-01 08:20 ` Ewan Young <kdbase.hack@gmail.com>
2026-07-02 03:27 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 1 reply; 656+ messages in thread
From: Ewan Young @ 2026-07-01 08:20 UTC (permalink / raw)
To: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>; +Cc: pgsql-hackers@lists.postgresql.org; Michael Paquier <michael@paquier.xyz>
Hi Bertrand,
On Wed, Jul 1, 2026 at 3:20 PM Bertrand Drouvot
<bertranddrouvot.pg@gmail.com> wrote:
>
> Hi hackers,
>
> While reviewing [1], I got segfault(s) because I created a custom statistics
> extension that I forgot to add to shared_preload_libraries. Then using one of
> its function produced:
>
> "
> Core was generated by `postgres: postgres postgres [local] SELECT '.
> Program terminated with signal SIGSEGV, Segmentation fault.
> #0 pgstat_init_entry (kind=kind@entry=24, shhashent=shhashent@entry=0x73f6c341a740) at pgstat_shmem.c:335
> 335 chunk = dsa_allocate_extended(pgStatLocal.dsa,
> "
>
> Indeed, if a custom statistics extension is loaded via CREATE EXTENSION without
> being listed in shared_preload_libraries, its _PG_init() skips the call to
> pgstat_register_kind(). The SQL functions are still created, and calling them
> invokes pgstat functions with a kind that was never registered.
>
> pgstat_get_kind_info() returns NULL in this case. The existing code only
> checked this via Assert() in some paths, so non-assert builds would dereference
> NULL and segfault.
>
> The attached patch adds runtime checks in all public-facing pgstat functions that
> accept a PgStat_Kind and dereference the returned kind info:
>
> - pgstat_prep_pending_entry()
> - pgstat_fetch_entry()
> - pgstat_reset()
> - pgstat_reset_of_kind()
> - pgstat_have_entry()
> - pgstat_snapshot_fixed()
> - pgstat_init_entry()
> - pgstat_reset_entry()
>
> Each now raises ERROR with ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE when
> the kind is not known or registered.
Thanks for the patch — nice catch, and the diagnosis looks right.
One small thing: in pgstat_snapshot_fixed(), the existing
Assert(pgstat_is_kind_valid(kind)); becomes redundant after the new NULL
check. A non-NULL kind_info already implies the kind is valid (that's the
only way pgstat_get_kind_info() returns non-NULL), so the assert can never
fire. Might as well drop it and keep just the fixed_amount one.
>
> [1]: https://postgr.es/m/akSi2txzLZWQL31Q%40bdtpg
>
> Regards,
>
> --
> Bertrand Drouvot
> PostgreSQL Contributors Team
> RDS Open Source Databases
> Amazon Web Services: https://aws.amazon.com
--
Regards,
Ewan Young
^ permalink raw reply [nested|flat] 656+ messages in thread
* Re: Prevent crash when calling pgstat functions with unregistered stats kind
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
@ 2026-07-02 03:27 ` Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 03:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
0 siblings, 1 reply; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-02 03:27 UTC (permalink / raw)
To: Ewan Young <kdbase.hack@gmail.com>; +Cc: pgsql-hackers@lists.postgresql.org; Michael Paquier <michael@paquier.xyz>
Hi Ewan,
On Wed, Jul 01, 2026 at 04:20:39PM +0800, Ewan Young wrote:
> Thanks for the patch — nice catch, and the diagnosis looks right.
Thanks for looking at it!
> One small thing: in pgstat_snapshot_fixed(), the existing
> Assert(pgstat_is_kind_valid(kind)); becomes redundant after the new NULL
> check. A non-NULL kind_info already implies the kind is valid (that's the
> only way pgstat_get_kind_info() returns non-NULL), so the assert can never
> fire. Might as well drop it and keep just the fixed_amount one.
Yeah good catch, done in the attached.
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 656+ messages in thread
* Re: Prevent crash when calling pgstat functions with unregistered stats kind
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
2026-07-02 03:27 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
@ 2026-07-02 03:43 ` Michael Paquier <michael@paquier.xyz>
2026-07-02 04:06 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 1 reply; 656+ messages in thread
From: Michael Paquier @ 2026-07-02 03:43 UTC (permalink / raw)
To: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>; +Cc: Ewan Young <kdbase.hack@gmail.com>; pgsql-hackers@lists.postgresql.org
On Thu, Jul 02, 2026 at 03:27:18AM +0000, Bertrand Drouvot wrote:
> On Wed, Jul 01, 2026 at 04:20:39PM +0800, Ewan Young wrote:
>> One small thing: in pgstat_snapshot_fixed(), the existing
>> Assert(pgstat_is_kind_valid(kind)); becomes redundant after the new NULL
>> check. A non-NULL kind_info already implies the kind is valid (that's the
>> only way pgstat_get_kind_info() returns non-NULL), so the assert can never
>> fire. Might as well drop it and keep just the fixed_amount one.
>
> Yeah good catch, done in the attached.
I am not convinced that it is worth bothering in the core code about
this class of failures; they are just not interesting, and impossible
to miss.
It seems to me that this error is in the _PG_init() of the modules in
modules/test_custom_stats/: we should not bypass the
pgstat_register_kind() if not loading the library from
shared_preload_libraries, but let the call happen and fail.
--
Michael
Attachments:
[application/pgp-signature] signature.asc (833B, ../../akXebziFr_eQgQi8@paquier.xyz/2-signature.asc)
download
^ permalink raw reply [nested|flat] 656+ messages in thread
* Re: Prevent crash when calling pgstat functions with unregistered stats kind
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
2026-07-02 03:27 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 03:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
@ 2026-07-02 04:06 ` Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:10 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
0 siblings, 1 reply; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-02 04:06 UTC (permalink / raw)
To: Michael Paquier <michael@paquier.xyz>; +Cc: Ewan Young <kdbase.hack@gmail.com>; pgsql-hackers@lists.postgresql.org
Hi,
On Thu, Jul 02, 2026 at 12:43:43PM +0900, Michael Paquier wrote:
> On Thu, Jul 02, 2026 at 03:27:18AM +0000, Bertrand Drouvot wrote:
> > On Wed, Jul 01, 2026 at 04:20:39PM +0800, Ewan Young wrote:
> >> One small thing: in pgstat_snapshot_fixed(), the existing
> >> Assert(pgstat_is_kind_valid(kind)); becomes redundant after the new NULL
> >> check. A non-NULL kind_info already implies the kind is valid (that's the
> >> only way pgstat_get_kind_info() returns non-NULL), so the assert can never
> >> fire. Might as well drop it and keep just the fixed_amount one.
> >
> > Yeah good catch, done in the attached.
>
> I am not convinced that it is worth bothering in the core code about
> this class of failures; they are just not interesting, and impossible
> to miss.
>
> It seems to me that this error is in the _PG_init() of the modules in
> modules/test_custom_stats/: we should not bypass the
> pgstat_register_kind() if not loading the library from
> shared_preload_libraries, but let the call happen and fail.
I agree that the responsibility should primarily be in the extension. However,
the issue is that the NULL dereference happens inside core code (pgstat_prep_pending_entry,
etc.), and the resulting segfault(s) cause the postmaster to terminate all
backends (not just the offending session).
Given that one misconfigured extension can crash all connections on the server,
a defensive check in core seems reasonable (kind of similar to 341e9a05e7b).
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 656+ messages in thread
* Re: Prevent crash when calling pgstat functions with unregistered stats kind
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
2026-07-02 03:27 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 03:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:06 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
@ 2026-07-02 04:10 ` Michael Paquier <michael@paquier.xyz>
2026-07-02 04:23 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 1 reply; 656+ messages in thread
From: Michael Paquier @ 2026-07-02 04:10 UTC (permalink / raw)
To: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>; +Cc: Ewan Young <kdbase.hack@gmail.com>; pgsql-hackers@lists.postgresql.org
On Thu, Jul 02, 2026 at 04:06:01AM +0000, Bertrand Drouvot wrote:
> I agree that the responsibility should primarily be in the extension. However,
> the issue is that the NULL dereference happens inside core code (pgstat_prep_pending_entry,
> etc.), and the resulting segfault(s) cause the postmaster to terminate all
> backends (not just the offending session).
>
> Given that one misconfigured extension can crash all connections on the server,
> a defensive check in core seems reasonable (kind of similar to 341e9a05e7b).
Nope, this was a different thing, doable in a couple of steps:
- Load the library.
- Write custom stats.
- Stop the server, flush the stats.
- Edit the configuration, not loading the library.
- Restart the server, loading failed.
The problem of this thread ought to be blocked at its source, in the
extension itself: let's not give free hands to an extension to do what
it should not be allowed to do. There is a similar defense in
test_custom_rmgrs, as one example. We should just map to that.
--
Michael
Attachments:
[application/pgp-signature] signature.asc (833B, ../../akXkqov6wLbKwpAd@paquier.xyz/2-signature.asc)
download
^ permalink raw reply [nested|flat] 656+ messages in thread
* Re: Prevent crash when calling pgstat functions with unregistered stats kind
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
2026-07-02 03:27 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 03:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:06 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:10 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
@ 2026-07-02 04:23 ` Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 1 reply; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-02 04:23 UTC (permalink / raw)
To: Michael Paquier <michael@paquier.xyz>; +Cc: Ewan Young <kdbase.hack@gmail.com>; pgsql-hackers@lists.postgresql.org
Hi,
On Thu, Jul 02, 2026 at 01:10:18PM +0900, Michael Paquier wrote:
> On Thu, Jul 02, 2026 at 04:06:01AM +0000, Bertrand Drouvot wrote:
> > I agree that the responsibility should primarily be in the extension. However,
> > the issue is that the NULL dereference happens inside core code (pgstat_prep_pending_entry,
> > etc.), and the resulting segfault(s) cause the postmaster to terminate all
> > backends (not just the offending session).
> >
> > Given that one misconfigured extension can crash all connections on the server,
> > a defensive check in core seems reasonable (kind of similar to 341e9a05e7b).
>
> Nope, this was a different thing, doable in a couple of steps:
> - Load the library.
> - Write custom stats.
> - Stop the server, flush the stats.
> - Edit the configuration, not loading the library.
> - Restart the server, loading failed.
>
> The problem of this thread ought to be blocked at its source, in the
> extension itself: let's not give free hands to an extension to do what
> it should not be allowed to do. There is a similar defense in
> test_custom_rmgrs, as one example. We should just map to that.
Ok but what about extensions that don't call pgstat_register_kind() at all? Your
point is that they would see the issue during the development of the extension? (If
so, I think I could agree).
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 656+ messages in thread
* Re: Prevent crash when calling pgstat functions with unregistered stats kind
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
2026-07-02 03:27 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 03:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:06 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:10 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:23 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
@ 2026-07-02 04:43 ` Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 05:00 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
0 siblings, 1 reply; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-02 04:43 UTC (permalink / raw)
To: Michael Paquier <michael@paquier.xyz>; +Cc: Ewan Young <kdbase.hack@gmail.com>; pgsql-hackers@lists.postgresql.org
On Thu, Jul 02, 2026 at 04:23:16AM +0000, Bertrand Drouvot wrote:
> Hi,
>
> On Thu, Jul 02, 2026 at 01:10:18PM +0900, Michael Paquier wrote:
> > On Thu, Jul 02, 2026 at 04:06:01AM +0000, Bertrand Drouvot wrote:
> > > I agree that the responsibility should primarily be in the extension. However,
> > > the issue is that the NULL dereference happens inside core code (pgstat_prep_pending_entry,
> > > etc.), and the resulting segfault(s) cause the postmaster to terminate all
> > > backends (not just the offending session).
> > >
> > > Given that one misconfigured extension can crash all connections on the server,
> > > a defensive check in core seems reasonable (kind of similar to 341e9a05e7b).
> >
> > Nope, this was a different thing, doable in a couple of steps:
> > - Load the library.
> > - Write custom stats.
> > - Stop the server, flush the stats.
> > - Edit the configuration, not loading the library.
> > - Restart the server, loading failed.
> >
> > The problem of this thread ought to be blocked at its source, in the
> > extension itself: let's not give free hands to an extension to do what
> > it should not be allowed to do. There is a similar defense in
> > test_custom_rmgrs, as one example. We should just map to that.
>
> Ok but what about extensions that don't call pgstat_register_kind() at all? Your
> point is that they would see the issue during the development of the extension? (If
> so, I think I could agree).
Something like in the attached?
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 656+ messages in thread
* Re: Prevent crash when calling pgstat functions with unregistered stats kind
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
2026-07-02 03:27 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 03:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:06 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:10 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:23 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
@ 2026-07-02 05:00 ` Michael Paquier <michael@paquier.xyz>
2026-07-02 05:02 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
0 siblings, 1 reply; 656+ messages in thread
From: Michael Paquier @ 2026-07-02 05:00 UTC (permalink / raw)
To: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>; +Cc: Ewan Young <kdbase.hack@gmail.com>; pgsql-hackers@lists.postgresql.org
On Thu, Jul 02, 2026 at 04:43:32AM +0000, Bertrand Drouvot wrote:
> On Thu, Jul 02, 2026 at 04:23:16AM +0000, Bertrand Drouvot wrote:
>> Ok but what about extensions that don't call pgstat_register_kind() at all? Your
>> point is that they would see the issue during the development of the extension? (If
>> so, I think I could agree).
Extensions doing custom stats have to call the register API, or
they're broken. This is the same assumption as custom RMGRs. There
are many ways to break the backend if you don't know what you do, just
take hooks for example. That's just one of them.
> Something like in the attached?
Yes, that looks OK here.
--
Michael
Attachments:
[application/pgp-signature] signature.asc (833B, ../../akXwVgoofSBd--pG@paquier.xyz/2-signature.asc)
download
^ permalink raw reply [nested|flat] 656+ messages in thread
* Re: Prevent crash when calling pgstat functions with unregistered stats kind
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
2026-07-02 03:27 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 03:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:06 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:10 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:23 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 05:00 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
@ 2026-07-02 05:02 ` Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 06:53 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
0 siblings, 1 reply; 656+ messages in thread
From: Bertrand Drouvot @ 2026-07-02 05:02 UTC (permalink / raw)
To: Michael Paquier <michael@paquier.xyz>; +Cc: Ewan Young <kdbase.hack@gmail.com>; pgsql-hackers@lists.postgresql.org
Hi,
On Thu, Jul 02, 2026 at 02:00:06PM +0900, Michael Paquier wrote:
> On Thu, Jul 02, 2026 at 04:43:32AM +0000, Bertrand Drouvot wrote:
> > On Thu, Jul 02, 2026 at 04:23:16AM +0000, Bertrand Drouvot wrote:
> >> Ok but what about extensions that don't call pgstat_register_kind() at all? Your
> >> point is that they would see the issue during the development of the extension? (If
> >> so, I think I could agree).
>
> Extensions doing custom stats have to call the register API, or
> they're broken. This is the same assumption as custom RMGRs. There
> are many ways to break the backend if you don't know what you do, just
> take hooks for example. That's just one of them.
>
> > Something like in the attached?
>
> Yes, that looks OK here.
That makes sense, I do agree.
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 656+ messages in thread
* Re: Prevent crash when calling pgstat functions with unregistered stats kind
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
2026-07-02 03:27 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 03:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:06 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:10 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:23 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 05:00 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 05:02 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
@ 2026-07-02 06:53 ` Michael Paquier <michael@paquier.xyz>
0 siblings, 0 replies; 656+ messages in thread
From: Michael Paquier @ 2026-07-02 06:53 UTC (permalink / raw)
To: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>; +Cc: Ewan Young <kdbase.hack@gmail.com>; pgsql-hackers@lists.postgresql.org
On Thu, Jul 02, 2026 at 05:02:36AM +0000, Bertrand Drouvot wrote:
> That makes sense, I do agree.
Done that now down to v19, thanks, in the shape of some pure code
deletion.
--
Michael
Attachments:
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^ permalink raw reply [nested|flat] 656+ messages in thread
end of thread, other threads:[~2026-07-02 06:53 UTC | newest]
Thread overview: 656+ messages (download: mbox mbox.gz follow: Atom feed)
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2024-01-22 09:45 [PATCH v13 7/8] Row pattern recognition patch (tests). Tatsuo Ishii <ishii@postgresql.org>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
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2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v2] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 05:43 [PATCH v1] Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 07:19 Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-01 08:20 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Ewan Young <kdbase.hack@gmail.com>
2026-07-02 03:27 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 03:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:06 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:10 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 04:23 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 04:43 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 05:00 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
2026-07-02 05:02 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
2026-07-02 06:53 ` Re: Prevent crash when calling pgstat functions with unregistered stats kind Michael Paquier <michael@paquier.xyz>
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