Avoid access to already-released lock in LockRefindAndRelease.

robertmhaas · robertmhaas · commit 18470e5f2f37 · 2014-07-24T08:39:46.000-04:00
Spotted by Tom Lane.
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
@@ -2878,7 +2878,7 @@ 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
`@@ -2878,7 +2878,7 @@ LockRefindAndRelease(LockMethod lockMethodTable, PGPROC *proc,`
`2878`	`2878`	`* Decrement strong lock count. This logic is needed only for 2PC.`
`2879`	`2879`	`*/`
`2880`	`2880`	`if (decrement_strong_lock_count`
`2881`		`- && ConflictsWithRelationFastPath(&lock->tag, lockmode))`
	`2881`	`+ && ConflictsWithRelationFastPath(locktag, lockmode))`
`2882`	`2882`	`{`
`2883`	`2883`	`uint32 fasthashcode = FastPathStrongLockHashPartition(hashcode);`
`2884`	`2884`