From: Colin Ian King colin.king@canonical.com
[ Upstream commit 9a5a85972c073f720d81a7ebd08bfe278e6e16db ]
Pointer mddev is being dereferenced with a test_bit call before mddev is being null checked, this may cause a null pointer dereference. Fix this by moving the null pointer checks to sanity check mddev before it is dereferenced.
Addresses-Coverity: ("Dereference before null check") Fixes: 62f7b1989c02 ("md raid0/linear: Mark array as 'broken' and fail BIOs if a member is gone") Signed-off-by: Colin Ian King colin.king@canonical.com Reviewed-by: Guilherme G. Piccoli gpiccoli@canonical.com Signed-off-by: Song Liu songliubraving@fb.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/md/md.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c index f567f536b529b..90756450b9588 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -470,17 +470,18 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio) struct mddev *mddev = bio->bi_disk->private_data; unsigned int sectors;
- if (unlikely(test_bit(MD_BROKEN, &mddev->flags)) && (rw == WRITE)) { + if (mddev == NULL || mddev->pers == NULL) { bio_io_error(bio); return BLK_QC_T_NONE; }
- blk_queue_split(q, &bio); - - if (mddev == NULL || mddev->pers == NULL) { + if (unlikely(test_bit(MD_BROKEN, &mddev->flags)) && (rw == WRITE)) { bio_io_error(bio); return BLK_QC_T_NONE; } + + blk_queue_split(q, &bio); + if (mddev->ro == 1 && unlikely(rw == WRITE)) { if (bio_sectors(bio) != 0) bio->bi_status = BLK_STS_IOERR;