4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Mike Snitzer <[email protected]> commit 4087a1fffe38106e10646606a27f10d40451862d upstream. 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: [email protected] Signed-off-by: Mike Snitzer <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/md/dm-rq.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -804,6 +804,10 @@ static void dm_old_request_fn(struct req 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); }
