From 9a5a85972c073f720d81a7ebd08bfe278e6e16db Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Thu, 2 Jul 2020 12:35:02 +0100
Subject: [PATCH] md: raid0/linear: fix dereference before null check on
pointer mddev
Git-commit: 9a5a85972c073f720d81a7ebd08bfe278e6e16db
Patch-mainline: v5.9-rc1
References: git fixes (block drivers)
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: Coly Li <colyli@suse.de>
---
drivers/md/md.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -384,17 +384,18 @@ static blk_qc_t md_make_request(struct r
unsigned int sectors;
int cpu;
- 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;