Re: [PATCH AUTOSEL 4.14 2/3] md: raid1: fix potential OOB in raid1_remove_disk()
From: Pavel Machek <hidden>
Date: 2023-09-11 22:11:29
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Hi!
From: Zhang Shurong <redacted>
[ 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.quoted hunk ↗ jump to hunk
+++ b/drivers/md/raid1.c@@ -1775,6 +1775,10 @@ 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)
Wow. Mixing declarations and code. I'm pretty sure that's not ok according to our coding style, and I'd be actually surprised if all our compiler configurations allowed this. Best regards, Pavel -- DENX Software Engineering GmbH, Managing Director: Erika Unter HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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