dm stats: fix divide by zero if 'number_of_areas' arg is zero
authorMikulas Patocka <mpatocka@redhat.com>
Fri, 5 Jun 2015 13:50:42 +0000 (09:50 -0400)
committerMike Snitzer <snitzer@redhat.com>
Wed, 17 Jun 2015 16:40:39 +0000 (12:40 -0400)
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+
drivers/md/dm-stats.c

index 492fe6a5ebf2ad5c7178157a1c48a73f390a071d..d1fd31a6dd1ab50112d80d48cd1328841b65ccdd 100644 (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++;