dm mpath: fix potential NULL pointer in feature arg processing

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>
Cc: stable@kernel.org

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index c3547016f0f1..adf851a081bd 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--;