From 6f01de256dd00fa2bd677950a841a9a44f7645d0 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Thu, 2 Jul 2020 12:35:02 +0100 Subject: [PATCH] md: raid0/linear: fix dereference before null check on pointer mddev [ 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 Reviewed-by: Guilherme G. Piccoli Signed-off-by: Song Liu Signed-off-by: Sasha Levin --- 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 5a378a453a2d..acef01e519d0 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -376,6 +376,11 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio) struct mddev *mddev = q->queuedata; unsigned int sectors; + if (mddev == NULL || mddev->pers == NULL) { + bio_io_error(bio); + return BLK_QC_T_NONE; + } + if (unlikely(test_bit(MD_BROKEN, &mddev->flags)) && (rw == WRITE)) { bio_io_error(bio); return BLK_QC_T_NONE; @@ -383,10 +388,6 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio) blk_queue_split(q, &bio); - if (mddev == NULL || mddev->pers == NULL) { - bio_io_error(bio); - return BLK_QC_T_NONE; - } if (mddev->ro == 1 && unlikely(rw == WRITE)) { if (bio_sectors(bio) != 0) bio->bi_status = BLK_STS_IOERR;