Commit 9a5a8597 authored Jul 02, 2020 by Colin Ian King Committed by Song Liu Jul 13, 2020

md: raid0/linear: fix dereference before null check on pointer mddev



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: 62f7b198 ("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>

parent 2eaac320

drivers/md/md.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -470,17 +470,18 @@ static blk_qc_t md_submit_bio(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(&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(&bio);

		if (mddev->ro == 1 && unlikely(rw == WRITE)) {
		if (bio_sectors(bio) != 0)
		bio->bi_status = BLK_STS_IOERR;

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