The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 1ebc2cec0b7dd8dad0812449110803bd875ac816 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka <mpatocka@xxxxxxxxxx> Date: Wed, 29 Jun 2022 13:40:01 -0400 Subject: [PATCH] dm raid: fix KASAN warning in raid5_remove_disk There's a KASAN warning in raid5_remove_disk when running the LVM testsuite. We fix this warning by verifying that the "number" variable is within limits. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 5d09256d7f81..ba289411f26f 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7933,7 +7933,7 @@ static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev) int err = 0; int number = rdev->raid_disk; struct md_rdev __rcu **rdevp; - struct disk_info *p = conf->disks + number; + struct disk_info *p; struct md_rdev *tmp; print_raid5_conf(conf); @@ -7952,6 +7952,9 @@ static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev) log_exit(conf); return 0; } + if (unlikely(number >= conf->pool_size)) + return 0; + p = conf->disks + number; if (rdev == rcu_access_pointer(p->rdev)) rdevp = &p->rdev; else if (rdev == rcu_access_pointer(p->replacement))
