Commit 5af3e8cc introduced a use-after-free at volumes.c:3139: bctl is freed
above in __cancel_balance() in all cases except for balance pause.  Fix this
by moving the offending check a couple statements above, the meaning of the
check is preserved.

Reported-by: Chris Mason <chris.ma...@fusionio.com>
Signed-off-by: Ilya Dryomov <idryo...@gmail.com>
---
 fs/btrfs/volumes.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 15f6efd..5d25aed 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3126,6 +3126,11 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
        mutex_lock(&fs_info->balance_mutex);
        atomic_dec(&fs_info->balance_running);
 
+       if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+               fs_info->num_tolerated_disk_barrier_failures =
+                       btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
+       }
+
        if (bargs) {
                memset(bargs, 0, sizeof(*bargs));
                update_ioctl_balance_args(fs_info, 0, bargs);
@@ -3136,11 +3141,6 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
                __cancel_balance(fs_info);
        }
 
-       if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
-               fs_info->num_tolerated_disk_barrier_failures =
-                       btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
-       }
-
        wake_up(&fs_info->balance_wait_q);
 
        return ret;
-- 
1.7.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to