[PATCH] md: enforce minimum of 2 disks for raid 4 and 5

[Ryan Mehri]

#syz test

Signed-off-by: Ryan Mehri <ryan....@gmail.com>
---
drivers/md/raid5.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ffb5fcde54a9..e02c579d4ceb 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -7541,6 +7541,12 @@ static struct r5conf *setup_conf(struct mddev *mddev)
mdname(mddev), mddev->new_layout);
return ERR_PTR(-EIO);
}
+ if ((mddev->new_level == 4 || mddev->new_level == 5)
+ && mddev->raid_disks < 2) {
+ pr_warn("md/raid:%s: not enough configured devices (%d, minimum 2)\n",
+ mdname(mddev), mddev->raid_disks);
+ return ERR_PTR(-EINVAL);
+ }
if (mddev->new_level == 6 && mddev->raid_disks < 4) {
pr_warn("md/raid:%s: not enough configured devices (%d, minimum 4)\n",
mdname(mddev), mddev->raid_disks);
--
2.55.0