From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
commit 98dba02d9a93eec11bffbb93c7c51624290702d2 upstream.
This command will crash with NULL pointer dereference:
dmsetup create flakey --table \
"0 `blockdev --getsize /dev/ram0` flakey /dev/ram0 0 0 1 2 corrupt_bio_byte 512"
Fix the crash by checking if arg_name is non-NULL before comparing it.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-flakey.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -125,9 +125,9 @@ static int parse_features(struct dm_arg_
* Direction r or w?
*/
arg_name = dm_shift_arg(as);
- if (!strcasecmp(arg_name, "w"))
+ if (arg_name && !strcasecmp(arg_name, "w"))
fc->corrupt_bio_rw = WRITE;
- else if (!strcasecmp(arg_name, "r"))
+ else if (arg_name && !strcasecmp(arg_name, "r"))
fc->corrupt_bio_rw = READ;
else {
ti->error = "Invalid corrupt bio direction (r or w)";
