From: Goldwyn Rodrigues <rgoldwyn@suse.com>
Date: Mon, 4 Dec 2017 03:14:12 +0000 (-0600)
Subject: dm flakey: check for null arg_name in parse_features()
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=7690e25302dc7d0cd42b349e746fe44b44a94f2b;p=openwrt%2Fstaging%2Fblogic.git

dm flakey: check for null arg_name in parse_features()

One can crash dm-flakey by specifying more feature arguments than the
number of features supplied.  Checking for null in arg_name avoids
this.

dmsetup create flakey-test --table "0 66076080 flakey /dev/sdb9 0 0 180 2 drop_writes"

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---

diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index b82cb1ab1eaa..1b907b15f5c3 100644
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -70,6 +70,11 @@ static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
 		arg_name = dm_shift_arg(as);
 		argc--;
 
+		if (!arg_name) {
+			ti->error = "Insufficient feature arguments";
+			return -EINVAL;
+		}
+
 		/*
 		 * drop_writes
 		 */