[Devel] [PATCH RHEL9 COMMIT] dm: Fix use-after-free in dm_cleanup_zoned_dev()

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.0-4.vz9.12.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh9-5.14.0-4.vz9.12.4
------>
commit 9e6cb851d44811975e6317d0b738603418082d9d
Author: Kirill Tkhai <ktkhai at virtuozzo.com>
Date:   Tue Feb 1 19:26:10 2022 +0300

    dm: Fix use-after-free in dm_cleanup_zoned_dev()
    
    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>
    Tested-by: Cyrill Gorcunov <gorcunov 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 2c5f9e585211..a678556c3da1 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);
 }
 
 /*