[PATCH 3.10 63/77] Btrfs: fix double free in find_lock_delalloc_range

From: Greg Kroah-Hartman
Date: Sat Jun 28 2014 - 15:03:51 EST


3.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Chris Mason <clm@xxxxxx>

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@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/btrfs/extent_io.c | 1 +
1 file changed, 1 insertion(+)

--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1624,6 +1624,7 @@ again:
* shortening the size of the delalloc range we're searching
*/
free_extent_state(cached_state);
+ cached_state = NULL;
if (!loops) {
unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
max_bytes = PAGE_CACHE_SIZE - offset;


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