dm mpath: validate hw_handler argument count

commit e094f4f15f5169526c7200b9bde44b900548a81e upstream.

Fix arg count parsing error in hw handlers.

Signed-off-by: Mikulas Patocka <mpatocka@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 736f1d97ea2c35ea4f28edbe54c9dacd4b00a854..774cc49239ffdf4872c2946e22e8e5fb0b148a0c 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -706,6 +706,11 @@ static int parse_hw_handler(struct arg_set *as, struct multipath *m)
        if (!hw_argc)
                return 0;
 
+       if (hw_argc > as->argc) {
+               ti->error = "not enough arguments for hardware handler";
+               return -EINVAL;
+       }
+
        m->hw_handler_name = kstrdup(shift(as), GFP_KERNEL);
        request_module("scsi_dh_%s", m->hw_handler_name);
        if (scsi_dh_handler_exist(m->hw_handler_name) == 0) {