Avoid access to already-released lock in LockRefindAndRelease.

robertmhaas · robertmhaas · commit b9fecd5330b6 · 2014-07-24T08:26:06.000-04:00
Spotted by Tom Lane.
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
@@ -2948,7 +2948,7 @@ LockRefindAndRelease(LockMethod lockMethodTable, PGPROC *proc,
 	 * Decrement strong lock count.  This logic is needed only for 2PC.
 	 */
 	if (decrement_strong_lock_count
-		&& ConflictsWithRelationFastPath(&lock->tag, lockmode))
+		&& ConflictsWithRelationFastPath(locktag, lockmode))
 	{
 		uint32		fasthashcode = FastPathStrongLockHashPartition(hashcode);
 

Original file line number	Diff line number	Diff line change
`@@ -2948,7 +2948,7 @@ LockRefindAndRelease(LockMethod lockMethodTable, PGPROC *proc,`
`2948`	`2948`	`* Decrement strong lock count. This logic is needed only for 2PC.`
`2949`	`2949`	`*/`
`2950`	`2950`	`if (decrement_strong_lock_count`
`2951`		`- && ConflictsWithRelationFastPath(&lock->tag, lockmode))`
	`2951`	`+ && ConflictsWithRelationFastPath(locktag, lockmode))`
`2952`	`2952`	`{`
`2953`	`2953`	`uint32 fasthashcode = FastPathStrongLockHashPartition(hashcode);`
`2954`	`2954`