[dm-devel] [PATCH] md-raid10: fix KASAN warning

[Mikulas Patocka]

There's a KASAN warning in raid10_remove_disk when running the lvm
test lvconvert-raid-reshape.sh. We fix this warning by verifying that the
value "number" is valid.

Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
Cc: stable at vger.kernel.org

---
 drivers/md/raid10.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Index: linux-2.6/drivers/md/raid10.c
===================================================================
--- linux-2.6.orig/drivers/md/raid10.c	2022-07-13 19:05:50.000000000 +0200
+++ linux-2.6/drivers/md/raid10.c	2022-07-13 19:07:05.000000000 +0200
@@ -2167,9 +2167,12 @@ static int raid10_remove_disk(struct mdd
 	int err = 0;
 	int number = rdev->raid_disk;
 	struct md_rdev **rdevp;
-	struct raid10_info *p = conf->mirrors + number;
+	struct raid10_info *p;
 
 	print_conf(conf);
+	if (unlikely(number >= mddev->raid_disks))
+		return 0;
+	p = conf->mirrors + number;
 	if (rdev == p->rdev)
 		rdevp = &p->rdev;
 	else if (rdev == p->replacement)