Commit 4087a1ff authored Jan 25, 2017 by Mike Snitzer

dm rq: cope with DM device destruction while in dm_old_request_fn()



Fixes a crash in dm_table_find_target() due to a NULL struct dm_table
being passed from dm_old_request_fn() that races with DM device
destruction.

Reported-by:  <artem@flashgrid.io>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org

parent d19a55cc

drivers/md/dm-rq.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -779,6 +779,10 @@ static void dm_old_request_fn(struct request_queue *q)
		int srcu_idx;
		struct dm_table *map = dm_get_live_table(md, &srcu_idx);

		if (unlikely(!map)) {
		dm_put_live_table(md, srcu_idx);
		return;
		}
		ti = dm_table_find_target(map, pos);
		dm_put_live_table(md, srcu_idx);
		}