[Devel] [PATCH RH9] dm: Fix use-after-free in dm_cleanup_zoned_dev()

[Kirill Tkhai]

dm_cleanup_zoned_dev() uses queue, so it must be called
before blk_cleanup_disk() starts its killing:

blk_cleanup_disk->blk_cleanup_queue()->kobject_put()->blk_release_queue()->
->...RCU...->blk_free_queue_rcu()->kmem_cache_free()

Otherwise, RCU callback may be executed first, and dm_cleanup_zoned_dev()
touches freed memory. See full KASAN trace in #PSBM-138227.

https://jira.sw.ru/browse/PSBM-138227
Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 drivers/md/dm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 2c5f9e5852117..a678556c3da18 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1699,6 +1699,7 @@ static void cleanup_mapped_device(struct mapped_device *md)
 	if (md->queue)
 		dm_queue_destroy_keyslot_manager(md->queue);
 
+	dm_cleanup_zoned_dev(md);
 	if (md->disk)
 		blk_cleanup_disk(md->disk);
 
@@ -1710,7 +1711,6 @@ static void cleanup_mapped_device(struct mapped_device *md)
 	mutex_destroy(&md->swap_bios_lock);
 
 	dm_mq_cleanup_mapped_device(md);
-	dm_cleanup_zoned_dev(md);
 }
 
 /*