[PATCH 5.16 0119/1017] dm: fix use-after-free in dm_cleanup_zoned_dev()

Greg Kroah-Hartman
2022-04-05T11:33:36Z

From: Kirill Tkhai <ktkhai@virtuozzo.com>

commit 588b7f5df0cb64f281290c7672470c006abe7160 upstream.

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() will touch free'd memory:

BUG: KASAN: use-after-free in dm_cleanup_zoned_dev+0x33/0xd0
Read of size 8 at addr ffff88805ac6e430 by task dmsetup/681

CPU: 4 PID: 681 Comm: dmsetup Not tainted 5.17.0-rc2+ #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x7d
print_address_description.constprop.0+0x1f/0x150
? dm_cleanup_zoned_dev+0x33/0xd0
kasan_report.cold+0x7f/0x11b
? dm_cleanup_zoned_dev+0x33/0xd0
dm_cleanup_zoned_dev+0x33/0xd0
__dm_destroy+0x26a/0x400
? dm_blk_ioctl+0x230/0x230
? up_write+0xd8/0x270
dev_remove+0x156/0x1d0
ctl_ioctl+0x269/0x530
? table_clear+0x140/0x140
? lock_release+0xb2/0x750
? remove_all+0x40/0x40
? rcu_read_lock_sched_held+0x12/0x70
? lock_downgrade+0x3c0/0x3c0
? rcu_read_lock_sched_held+0x12/0x70
dm_ctl_ioctl+0xa/0x10
__x64_sys_ioctl+0xb9/0xf0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fb6dfa95c27

Fixes: bb37d77239af ("dm: introduce zone append emulation")
Cc: stable@vger.kernel.org
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/md/dm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1676,6 +1676,7 @@ static void cleanup_mapped_device(struct
md->dax_dev = NULL;
}

+ dm_cleanup_zoned_dev(md);
if (md->disk) {
spin_lock(&_minor_lock);
md->disk->private_data = NULL;
@@ -1696,7 +1697,6 @@ static void cleanup_mapped_device(struct
mutex_destroy(&md->swap_bios_lock);

dm_mq_cleanup_mapped_device(md);
- dm_cleanup_zoned_dev(md);
}

/*