From 0dbb3dc1bd66c63730696b69fbe768024c8bfb04 Mon Sep 17 00:00:00 2001 From: Bertrand Drouvot Date: Sat, 2 Nov 2024 14:21:18 +0000 Subject: [PATCH v6 1/2] Clear padding in PgStat_HashKey keys 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