dm clone: Fix UAF in clone_dtr()

commit e4b5957c6f749a501c464f92792f1c8e26b61a94 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/dm-clone-target.c b/drivers/md/dm-clone-target.c
index edd22e4d65dffd41d097e8f96d3659303c13425a..ec4f2487ef10d3605e3444c0aab50bea1baba8f7 100644 (file)
--- a/drivers/md/dm-clone-target.c
+++ b/drivers/md/dm-clone-target.c
@@ -1959,6 +1959,7 @@ 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);