Patch "dm stats: fix divide by zero if 'number_of_areas' arg is zero" has been added to the 4.1-stable tree

Patch "dm stats: fix divide by zero if 'number_of_areas' arg is zero" has been added to the 4.1-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

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

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     dm-stats-fix-divide-by-zero-if-number_of_areas-arg-is-zero.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From dd4c1b7d0c95be1c9245118a3accc41a16f1db67 Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@redhat.com>
Date: Fri, 5 Jun 2015 09:50:42 -0400
Subject: dm stats: fix divide by zero if 'number_of_areas' arg is zero

From: Mikulas Patocka <mpatocka@redhat.com>

commit dd4c1b7d0c95be1c9245118a3accc41a16f1db67 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/dm-stats.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/md/dm-stats.c
+++ b/drivers/md/dm-stats.c
@@ -795,6 +795,8 @@ static int message_stats_create(struct m
 		return -EINVAL;
 
 	if (sscanf(argv[2], "/%u%c", &divisor, &dummy) == 1) {
+		if (!divisor)
+			return -EINVAL;
 		step = end - start;
 		if (do_div(step, divisor))
 			step++;


Patches currently in stable-queue which might be from mpatocka@redhat.com are

queue-4.1/dm-stats-fix-divide-by-zero-if-number_of_areas-arg-is-zero.patch
queue-4.1/libata-increase-the-timeout-when-setting-transfer-mode.patch