From: Colin King <colin.king@canonical.com>
To: Song Liu <song@kernel.org>, NeilBrown <neilb@suse.de>,
"Guilherme G . Piccoli" <gpiccoli@canonical.com>,
linux-raid@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] md: raid0/linear: fix dereference before null check on pointer mddev
Date: Thu, 02 Jul 2020 11:35:02 +0000 [thread overview]
Message-ID: <20200702113502.37408-1-colin.king@canonical.com> (raw)
From: Colin Ian King <colin.king@canonical.com>
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>
---
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 8bb69c61afe0..49452149ac72 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -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;
--
2.27.0
next reply other threads:[~2020-07-02 11:35 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-02 11:35 Colin King [this message]
2020-07-02 14:40 ` [PATCH] md: raid0/linear: fix dereference before null check on pointer mddev Guilherme Piccoli
2020-07-02 18:36 ` Song Liu
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