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

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Subject: [PATCH] md: enforce minimum of 2 disks for raid 4 and 5
Author: ryan.mehri1@gmail.com

#syz test

Signed-off-by: Ryan Mehri <ryan.mehri1@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