[PATCH 4.19 95/98] dm zoned: fix potential NULL dereference in dmz_do_reclaim()

[Greg Kroah-Hartman]

[ Upstream commit e0702d90b79d430b0ccc276ead4f88440bb51352 ]

This function is supposed to return error pointers so it matches the
dmz_get_rnd_zone_for_reclaim() function.  The current code could lead to
a NULL dereference in dmz_do_reclaim()

Fixes: b234c6d7a703 ("dm zoned: improve error handling in reclaim")
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
Reviewed-by: Dmitry Fomichev <dmitry.fomic...@wdc.com>
Signed-off-by: Mike Snitzer <snit...@redhat.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/md/dm-zoned-metadata.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index 00e7a343eacf1..7e8d7fc99410d 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -1579,7 +1579,7 @@ static struct dm_zone 
*dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd)
        struct dm_zone *zone;
 
        if (list_empty(&zmd->map_seq_list))
-               return NULL;
+               return ERR_PTR(-EBUSY);
 
        list_for_each_entry(zone, &zmd->map_seq_list, link) {
                if (!zone->bzone)
@@ -1588,7 +1588,7 @@ static struct dm_zone 
*dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd)
                        return zone;
        }
 
-       return NULL;
+       return ERR_PTR(-EBUSY);
 }
 
 /*
-- 
2.20.1