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-Tag: v3.16.83~189
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=30f2093f85b5eab51c3956969c2d2fce68e5e165;p=thirdparty%2Fkernel%2Fstable.git

dm flakey: check for null arg_name in parse_features()

commit 7690e25302dc7d0cd42b349e746fe44b44a94f2b upstream.

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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index 3087adb25ab7e..8809c5e6f6ac3 100644
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -69,6 +69,11 @@ 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
 		 */