[PATCH 4.14 125/199] dm flakey: check for null arg_name in parse_features()

From: Greg Kroah-Hartman
Date: Wed Apr 22 2020 - 06:49:43 EST


From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>

[ Upstream commit 7690e25302dc7d0cd42b349e746fe44b44a94f2b ]

One can crash dm-flakey by specifying more feature arguments than the
number of features supplied. Checking for null in arg_name avoids
this.

dmsetup create flakey-test --table "0 66076080 flakey /dev/sdb9 0 0 180 2 drop_writes"

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/md/dm-flakey.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index b1b68e01b889c..53cd31199f212 100644
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -70,6 +70,11 @@ static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
arg_name = dm_shift_arg(as);
argc--;

+ if (!arg_name) {
+ ti->error = "Insufficient feature arguments";
+ return -EINVAL;
+ }
+
/*
* drop_writes
*/
--
2.20.1