[patch 095/108] dm mpath: validate table argument count

Greg KH
2009-07-01T01:14:58Z

[-- Attachment #1: dm-mpath-validate-table-argument-count.patch --]
[-- Type: text/plain, Size: 1161 bytes --]

2.6.30-stable review patch. If anyone has any objections, please let us know.

------------------

From: Mikulas Patocka <mpatocka@redhat.com>

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>

---
drivers/md/dm-mpath.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -553,6 +553,12 @@ static int parse_path_selector(struct ar
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);