[PATCH 5.4 30/54] dm: fix bug with RCU locking in dm_blk_report_zones

Greg Kroah-Hartman
2020-12-10T14:41:59Z

From: Sergei Shtepa <sergei.shtepa@veeam.com>

commit 89478335718c98557f10470a9bc5c555b9261c4e upstream.

The dm_get_live_table() function makes RCU read lock so
dm_put_live_table() must be called even if dm_table map is not found.

Fixes: e76239a3748c9 ("block: add a report_zones method")
Cc: stable@vger.kernel.org
Signed-off-by: Sergei Shtepa <sergei.shtepa@veeam.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/md/dm.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -455,8 +455,10 @@ static int dm_blk_report_zones(struct ge
return -EAGAIN;

map = dm_get_live_table(md, &srcu_idx);
- if (!map)
- return -EIO;
+ if (!map) {
+ ret = -EIO;
+ goto out;
+ }

tgt = dm_table_find_target(map, sector);
if (!tgt) {