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

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+
This commit is contained in:
Mikulas Patocka 2015-06-05 09:50:42 -04:00 committed by Mike Snitzer
parent bccab6a01a
commit dd4c1b7d0c

View File

@ -792,6 +792,8 @@ 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++;