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help / color / mirror / Atom feedFrom: Bertrand Drouvot <[email protected]>
Subject: [PATCH v6 1/2] Clear padding in PgStat_HashKey keys
Date: Sat, 2 Nov 2024 14:21:18 +0000
PgStat_HashKey keys are currently initialized in a way that could result in random
data in the padding bytes (if there was padding in PgStat_HashKey which is not
the case currently).
We are using sizeof(PgStat_HashKey) in pgstat_cmp_hash_key() and we compute the
hash hash key in pgstat_hash_hash_key() using the PgStat_HashKey struct size as
input. So, we have to ensure that no random data can be stored in the padding
bytes (if any) of a PgStat_HashKey key.
---
src/backend/utils/activity/pgstat.c | 3 +++
src/backend/utils/activity/pgstat_shmem.c | 18 ++++++++++++++++--
2 files changed, 19 insertions(+), 2 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index be48432cc3..ea8c5691e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -938,6 +938,9 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
pgstat_prep_snapshot();
+ /* clear padding */
+ memset(&key, 0, sizeof(struct PgStat_HashKey));
+
key.kind = kind;
key.dboid = dboid;
key.objid = objid;
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index a09c6fee05..c1b7ff76b1 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -432,11 +432,18 @@ PgStat_EntryRef *
pgstat_get_entry_ref(PgStat_Kind kind, Oid dboid, uint64 objid, bool create,
bool *created_entry)
{
- PgStat_HashKey key = {.kind = kind,.dboid = dboid,.objid = objid};
+ PgStat_HashKey key;
PgStatShared_HashEntry *shhashent;
PgStatShared_Common *shheader = NULL;
PgStat_EntryRef *entry_ref;
+ /* clear padding */
+ memset(&key, 0, sizeof(struct PgStat_HashKey));
+
+ key.kind = kind;
+ key.dboid = dboid;
+ key.objid = objid;
+
/*
* passing in created_entry only makes sense if we possibly could create
* entry.
@@ -908,10 +915,17 @@ pgstat_drop_database_and_contents(Oid dboid)
bool
pgstat_drop_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
{
- PgStat_HashKey key = {.kind = kind,.dboid = dboid,.objid = objid};
+ PgStat_HashKey key;
PgStatShared_HashEntry *shent;
bool freed = true;
+ /* clear padding */
+ memset(&key, 0, sizeof(struct PgStat_HashKey));
+
+ key.kind = kind;
+ key.dboid = dboid;
+ key.objid = objid;
+
/* delete local reference */
if (pgStatEntryRefHash)
{
--
2.34.1
--gvmrl0mfoTEJEfPE
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment;
filename="v6-0002-Provide-relfilenode-statistics.patch"
Content-Transfer-Encoding: 8bit
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