Subject: Fix overflow in justify_interval related functions

From: Joseph Koshakow <[email-masked]>
Date: Sun, 13 Feb 2022 13:28:38 -0500

I mentioned this issue briefly in another thread, but the
justify_interval, justify_days, and justify_hours functions
all have the potential to overflow. The attached patch fixes
this issue.

Cheers,
Joe Koshakow
From 4400f2e6886097e3b75d455aeec1ffa9cbc88510 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <[email-masked]>
Date: Sun, 13 Feb 2022 13:26:16 -0500
Subject: [PATCH] Check for overflow in justify_interval functions

justify_interval, justify_hours, and justify_days didn't check for
overflow when moving hours to days or days to hours. This commit adds
check for overflow and returns an appropriate error.
---
 src/backend/utils/adt/timestamp.c      | 20 ++++++++++++++++----
 src/test/regress/expected/interval.out |  8 ++++++++
 src/test/regress/sql/interval.sql      |  6 ++++++
 3 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 36f8a84bcc..fb4b3ae0aa 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -2718,11 +2718,17 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->time = span->time;
 
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
-	result->day += wholeday;	/* could overflow... */
+	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				errmsg("interval out of range")));
 
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
-	result->month += wholemonth;
+	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				errmsg("interval out of range")));
 
 	if (result->month > 0 &&
 		(result->day < 0 || (result->day == 0 && result->time < 0)))
@@ -2772,7 +2778,10 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->time = span->time;
 
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
-	result->day += wholeday;	/* could overflow... */
+	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				errmsg("interval out of range")));
 
 	if (result->day > 0 && result->time < 0)
 	{
@@ -2808,7 +2817,10 @@ interval_justify_days(PG_FUNCTION_ARGS)
 
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
-	result->month += wholemonth;
+	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				errmsg("interval out of range")));
 
 	if (result->month > 0 && result->day < 0)
 	{
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index accd4a7d90..e2bb8095c3 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -396,6 +396,10 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
  @ 7 mons 6 days 5 hours 4 mins 3 secs
 (1 row)
 
+SELECT justify_hours(interval '2147483647 days 24 hrs');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483647 months 30 days');
+ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
   1 month -1 hour   
@@ -403,6 +407,10 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
  @ 29 days 23 hours
 (1 row)
 
+SELECT justify_interval(interval '2147483647 days 24 hrs');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483647 months 30 days');
+ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
 SET IntervalStyle TO postgres;
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 6d532398bd..3ebdca5023 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -149,10 +149,16 @@ select '100000000y 10mon -1000000000d -100000h -10min -10.000001s ago'::interval
 SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as "6 mons 5 days 4 hours 3 mins 2 seconds";
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
+SELECT justify_hours(interval '2147483647 days 24 hrs');
+SELECT justify_days(interval '2147483647 months 30 days');
+
 -- test justify_interval()
 
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
+SELECT justify_interval(interval '2147483647 days 24 hrs');
+SELECT justify_interval(interval '2147483647 months 30 days');
+
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
 SET IntervalStyle TO postgres;
-- 
2.25.1