Commit 12849ed1 authored Apr 18, 2023 by Mikulas Patocka Committed by Greg Kroah-Hartman May 17, 2023

dm flakey: fix a crash with invalid table line



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@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ca8b634f

drivers/md/dm-flakey.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -124,9 +124,9 @@ static int parse_features(struct dm_arg_set as, struct flakey_c fc,
		* 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)";