[PATCH AUTOSEL 6.4 27/31] md: raid1: fix potential OOB in raid1_remove_disk()

Sasha Levin
2023-09-08T19:34:29Z

From: Zhang Shurong <zhang_shurong@foxmail.com>

[ Upstream commit 8b0472b50bcf0f19a5119b00a53b63579c8e1e4d ]

If rddev->raid_disk is greater than mddev->raid_disks, there will be
an out-of-bounds in raid1_remove_disk(). We have already found
similar reports as follows:

1) commit d17f744e883b ("md-raid10: fix KASAN warning")
2) commit 1ebc2cec0b7d ("dm raid: fix KASAN warning in raid5_remove_disk")

Fix this bug by checking whether the "number" variable is
valid.

Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/tencent_0D24426FAC6A21B69AC0C03CE4143A508F09@qq.com
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/md/raid1.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index e51b77a3a8397..d890e15230d21 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1826,6 +1826,10 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
struct r1conf *conf = mddev->private;
int err = 0;
int number = rdev->raid_disk;
+
+ if (unlikely(number >= conf->raid_disks))
+ goto abort;
+
struct raid1_info *p = conf->mirrors + number;

if (rdev != p->rdev)
--
2.40.1