Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.2 31/45] dm zoned: fix invalid memory access | Date | Sun, 29 Sep 2019 15:55:59 +0200 |
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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 ff3fd011796ed..3334f5865de77 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, refcount_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; -- 2.20.1
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