dm clone: Fix UAF in clone_dtr()

Dm_clone also has the same UAF problem when dm_resume()
and dm_destroy() are concurrent.

Therefore, cancelling timer again in clone_dtr().

Cc: stable@vger.kernel.org
Fixes: 7431b7835f554 ("dm: add clone target")
Signed-off-by: Luo Meng <luomeng12@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

diff --git a/drivers/md/dm-clone-target.c b/drivers/md/dm-clone-target.c
index 2f1cc66..29e0b85 100644 (file)
--- a/drivers/md/dm-clone-target.c
+++ b/drivers/md/dm-clone-target.c
@@ -1958,6 +1958,7 @@ static void clone_dtr(struct dm_target *ti)
 
        mempool_exit(&clone->hydration_pool);
        dm_kcopyd_client_destroy(clone->kcopyd_client);
+       cancel_delayed_work_sync(&clone->waker);
        destroy_workqueue(clone->wq);
        hash_table_exit(clone);
        dm_clone_metadata_close(clone->cmd);