From: Mikulas Patocka <mpatocka@redhat.com>
Date: Mon, 22 Jun 2009 09:08:02 +0000 (+0100)
Subject: dm mpath: validate table argument count
X-Git-Tag: v2.6.29.6~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4869fdea77052c480c54b9e66a927ba036eab29e;p=thirdparty%2Fkernel%2Fstable.git

dm mpath: validate table argument count

commit 0e0497c0c017664994819f4602dc07fd95896c52 upstream.

The parser reads the argument count as a number but doesn't check that
sufficient arguments are supplied. This command triggers the bug:

dmsetup create mpath --table "0 `blockdev --getsize /dev/mapper/cr0`
    multipath 0 0 2 1 round-robin 1000 0 1 1 /dev/mapper/cr0
    round-robin 0 1 1 /dev/mapper/cr1 1000"
kernel BUG at drivers/md/dm-mpath.c:530!

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 095f77bf96819..736f1d97ea2c3 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -554,6 +554,12 @@ static int parse_path_selector(struct arg_set *as, struct priority_group *pg,
 		return -EINVAL;
 	}
 
+	if (ps_argc > as->argc) {
+		dm_put_path_selector(pst);
+		ti->error = "not enough arguments for path selector";
+		return -EINVAL;
+	}
+
 	r = pst->create(&pg->ps, ps_argc, as->argv);
 	if (r) {
 		dm_put_path_selector(pst);