On Mon, 26 Aug 2019, Damien Le Moal wrote: > On 2019/08/26 15:41, Mikulas Patocka wrote: > > The patch 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. > > > > Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> > > Cc: stable@xxxxxxxxxxxxxxx We should also append this line: Fixes: 75d66ffb48ef ("dm zoned: properly handle backing device failure") Mikulas > > --- > > drivers/md/dm-zoned-target.c | 2 -- > > 1 file changed, 2 deletions(-) > > > > Index: linux-2.6/drivers/md/dm-zoned-target.c > > =================================================================== > > --- linux-2.6.orig/drivers/md/dm-zoned-target.c 2019-08-26 08:30:30.000000000 +0200 > > +++ linux-2.6/drivers/md/dm-zoned-target.c 2019-08-26 08:36:23.000000000 +0200 > > @@ -134,8 +134,6 @@ static int dmz_submit_bio(struct dmz_tar > > > > 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; > > > > Argh... Indeed. Thanks Mikulas. > > Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx> > > -- > Damien Le Moal > Western Digital Research > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel