dm mpath: validate table argument count
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!
Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 6a386ab..d880299 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -553,6 +553,12 @@
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);