From 7855e3447a166f5a24d2b95dc2633f7fb9eb6cc9 Mon Sep 17 00:00:00 2001
From: Chris Mason <clm@fb.com>
Date: Wed, 21 May 2014 05:49:54 -0700
Subject: [PATCH] Btrfs: fix double free in find_lock_delalloc_range

commit 7d78874273463a784759916fc3e0b4e2eb141c70 upstream.

We need to NULL the cached_state after freeing it, otherwise
we might free it again if find_delalloc_range doesn't find anything.

Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 fs/btrfs/extent_io.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 51731b76900d..0d611d1e2e34 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1645,6 +1645,7 @@ static noinline u64 find_lock_delalloc_range(struct inode *inode,
 		 * shortening the size of the delalloc range we're searching
 		 */
 		free_extent_state(cached_state);
+		cached_state = NULL;
 		if (!loops) {
 			max_bytes = PAGE_CACHE_SIZE;
 			loops = 1;
-- 
2.30.9