From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Tue, 13 May 2014 16:17:28 +0000 (+0300)
Subject: Fix harmless access to uninitialized memory.
X-Git-Tag: REL9_4_BETA2~200
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f35aef415aa755c4e99f8c0ef83f9d14dbc48bb4;p=postgresql

Fix harmless access to uninitialized memory.

When cache invalidations arrive while ri_LoadConstraintInfo() is busy
filling a new cache entry, InvalidateConstraintCacheCallBack() compares
the - not yet initialized - oidHashValue field with the to-be-invalidated
hash value. To fix, check whether the entry is already marked as invalid.

Andres Freund
---

diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
index d30847b34e..e4d7b2c34b 100644
--- a/src/backend/utils/adt/ri_triggers.c
+++ b/src/backend/utils/adt/ri_triggers.c
@@ -2934,7 +2934,8 @@ InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue)
 	hash_seq_init(&status, ri_constraint_cache);
 	while ((hentry = (RI_ConstraintInfo *) hash_seq_search(&status)) != NULL)
 	{
-		if (hashvalue == 0 || hentry->oidHashValue == hashvalue)
+		if (hentry->valid &&
+			(hashvalue == 0 || hentry->oidHashValue == hashvalue))
 			hentry->valid = false;
 	}
 }