[PATCH 4.9 201/206] xfs: fix double-cleanup when CUI recovery fails

From: Greg Kroah-Hartman
Date: Tue Jan 10 2017 - 08:55:12 EST


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

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


From: "Darrick J. Wong" <darrick.wong@xxxxxxxxxx>

commit 7a21272b088894070391a94fdd1c67014020fa1d upstream.

Dan Carpenter reported a double-free of rcur if _defer_finish fails
while we're recovering CUI items. Fix the error recovery to prevent
this.

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/xfs_refcount_item.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/xfs/xfs_refcount_item.c
+++ b/fs/xfs/xfs_refcount_item.c
@@ -526,13 +526,14 @@ xfs_cui_recover(
xfs_refcount_finish_one_cleanup(tp, rcur, error);
error = xfs_defer_finish(&tp, &dfops, NULL);
if (error)
- goto abort_error;
+ goto abort_defer;
set_bit(XFS_CUI_RECOVERED, &cuip->cui_flags);
error = xfs_trans_commit(tp);
return error;

abort_error:
xfs_refcount_finish_one_cleanup(tp, rcur, error);
+abort_defer:
xfs_defer_cancel(&dfops);
xfs_trans_cancel(tp);
return error;