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 <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>
Cc: [email protected] # v3.12+
diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c
index 492fe6a..d1fd31a 100644
--- a/drivers/md/dm-stats.c
+++ b/drivers/md/dm-stats.c
@@ -792,6 +792,8 @@
return -EINVAL;
if (sscanf(argv[2], "/%u%c", &divisor, &dummy) == 1) {
+ if (!divisor)
+ return -EINVAL;
step = end - start;
if (do_div(step, divisor))
step++;
