From: Mike Snitzer <snitzer@redhat.com>
Date: Tue, 2 Aug 2011 11:32:00 +0000 (+0100)
Subject: dm mpath: fix potential NULL pointer in feature arg processing
X-Git-Tag: firefly_0821_release~7541^2~3024
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=eb81cf19f5740d1397a72d1abb59570e1dda2711;p=firefly-linux-kernel-4.4.55.git

dm mpath: fix potential NULL pointer in feature arg processing

commit 286f367dad40beb3234a18c17391d03ba939a7f3 upstream.

Avoid dereferencing a NULL pointer if the number of feature arguments
supplied is fewer than indicated.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index aa4e570c2cb5..209991bebd30 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -807,6 +807,11 @@ static int parse_features(struct arg_set *as, struct multipath *m)
 	if (!argc)
 		return 0;
 
+	if (argc > as->argc) {
+		ti->error = "not enough arguments for features";
+		return -EINVAL;
+	}
+
 	do {
 		param_name = shift(as);
 		argc--;