Commit 83891b4c authored Jun 05, 2015 by Mikulas Patocka Committed by Sasha Levin Jul 03, 2015

dm stats: fix divide by zero if 'number_of_areas' arg is zero



[ Upstream commit dd4c1b7d0c95be1c9245118a3accc41a16f1db67 ]

If the number_of_areas argument was zero the kernel would crash on
div-by-zero.  Add better input validation.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.12+
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent c9fdda04

drivers/md/dm-stats.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -795,6 +795,8 @@ static int message_stats_create(struct mapped_device *md,
		return -EINVAL;

		if (sscanf(argv[2], "/%u%c", &divisor, &dummy) == 1) {
		if (!divisor)
		return -EINVAL;
		step = end - start;
		if (do_div(step, divisor))
		step++;