Fix harmless access to uninitialized memory.

hlinnaka · hlinnaka · commit f35aef415aa7 · 2014-05-13T19:18:28.000+03:00
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
@@ -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;
 	}
 }

Original file line number	Diff line number	Diff line change
`@@ -2934,7 +2934,8 @@ InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue)`
`2934`	`2934`	`hash_seq_init(&status, ri_constraint_cache);`
`2935`	`2935`	`while ((hentry = (RI_ConstraintInfo *) hash_seq_search(&status)) != NULL)`
`2936`	`2936`	`{`
`2937`		`- if (hashvalue == 0 \|\| hentry->oidHashValue == hashvalue)`
	`2937`	`+ if (hentry->valid &&`
	`2938`	`+ (hashvalue == 0 \|\| hentry->oidHashValue == hashvalue))`
`2938`	`2939`	`hentry->valid = false;`
`2939`	`2940`	`}`
`2940`	`2941`	`}`