From: Mikulas Patocka mpatocka@redhat.com
[ Upstream commit 0c8e9c2d668278652af028c3cc068c65f66342f4 ]
Commit 75d66ffb48efb30f2dd42f041ba8b39c5b2bd115 ("dm zoned: properly handle backing device failure") triggers a coverity warning:
*** CID 1452808: Memory - illegal accesses (USE_AFTER_FREE) /drivers/md/dm-zoned-target.c: 137 in dmz_submit_bio() 131 clone->bi_private = bioctx; 132 133 bio_advance(bio, clone->bi_iter.bi_size); 134 135 refcount_inc(&bioctx->ref); 136 generic_make_request(clone);
CID 1452808: Memory - illegal accesses (USE_AFTER_FREE) Dereferencing freed pointer "clone".
137 if (clone->bi_status == BLK_STS_IOERR) 138 return -EIO; 139 140 if (bio_op(bio) == REQ_OP_WRITE && dmz_is_seq(zone)) 141 zone->wp_block += nr_blocks; 142
The "clone" bio may be processed and freed before the check "clone->bi_status == BLK_STS_IOERR" - so this check can access invalid memory.
Fixes: 75d66ffb48efb3 ("dm zoned: properly handle backing device failure") Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka mpatocka@redhat.com Reviewed-by: Damien Le Moal damien.lemoal@wdc.com Signed-off-by: Mike Snitzer snitzer@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/md/dm-zoned-target.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c index 1e004d975e786..4694763f9d404 100644 --- a/drivers/md/dm-zoned-target.c +++ b/drivers/md/dm-zoned-target.c @@ -133,8 +133,6 @@ static int dmz_submit_bio(struct dmz_target *dmz, struct dm_zone *zone,
atomic_inc(&bioctx->ref); generic_make_request(clone); - if (clone->bi_status == BLK_STS_IOERR) - return -EIO;
if (bio_op(bio) == REQ_OP_WRITE && dmz_is_seq(zone)) zone->wp_block += nr_blocks;