4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Qu Wenruo <quwen...@cn.fujitsu.com>
commit 0a95b851370b84a4b9d92ee6d1fa0926901d0454 upstream.
Parameter of trace_btrfs_work_queued() can be freed in its workqueue.
So no one use use that pointer after queue_work().
Fix the user-after-free bug by move the trace line before queue_work().
Reported-by: Dave Jones <da...@codemonkey.org.uk>
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
Reviewed-by: David Sterba <dste...@suse.com>
Signed-off-by: Chris Mason <c...@fb.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
fs/btrfs/async-thread.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -328,8 +328,8 @@ static inline void __btrfs_queue_work(st
list_add_tail(&work->ordered_list, &wq->ordered_list);
spin_unlock_irqrestore(&wq->list_lock, flags);
}
- queue_work(wq->normal_wq, &work->normal_work);
trace_btrfs_work_queued(work);
+ queue_work(wq->normal_wq, &work->normal_work);
}
void btrfs_queue_work(struct btrfs_workqueue *wq,
