[PATCH 6.18 245/641] dm: fix unlocked test for dm_suspended_md

Greg Kroah-Hartman
2026-02-25T01:46:30Z

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Mikulas Patocka <mpatocka@redhat.com>

[ Upstream commit 24c405fdbe215c45e57bba672cc42859038491ee ]

The function dm_blk_report_zones tests if the device is suspended with
the "dm_suspended_md" call. However, this function is called without
holding any locks, so the device may be suspended just after it.

Move the call to dm_suspended_md after dm_get_live_table, so that the
device can't be suspended after the suspended state was tested.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 37f53a2c60d0 ("dm: fix dm_blk_report_zones")
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/md/dm-zone.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm-zone.c b/drivers/md/dm-zone.c
index 78e17dd4d01b8..ba39c8313f32b 100644
--- a/drivers/md/dm-zone.c
+++ b/drivers/md/dm-zone.c
@@ -66,11 +66,13 @@ int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
* Zone revalidation during __bind() is in progress, but this
* call is from a different process
*/
- if (dm_suspended_md(md))
- return -EAGAIN;
-
map = dm_get_live_table(md, &srcu_idx);
put_table = true;
+
+ if (dm_suspended_md(md)) {
+ ret = -EAGAIN;
+ goto do_put_table;
+ }
} else {
/* Zone revalidation during __bind() */
map = zone_revalidate_map;
@@ -80,6 +82,7 @@ int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
ret = dm_blk_do_report_zones(md, map, sector, nr_zones, cb,
data);

+do_put_table:
if (put_table)
dm_put_live_table(md, srcu_idx);

--
2.51.0