Patch "net/packet: fix overflow in check for tp_frame_nr" has been added to the 3.18-stable tree

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

net/packet: fix overflow in check for tp_frame_nr

to the 3.18-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:
net-packet-fix-overflow-in-check-for-tp_frame_nr.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Andrey Konovalov <[email protected]>
Date: Wed, 29 Mar 2017 16:11:21 +0200
Subject: net/packet: fix overflow in check for tp_frame_nr

From: Andrey Konovalov <[email protected]>

[ Upstream commit 8f8d28e4d6d815a391285e121c3a53a0b6cb9e7b ]

When calculating rb->frames_per_block * req->tp_block_nr the result can overflow.

Add a check that tp_block_size * tp_block_nr <= UINT_MAX.

Since frames_per_block <= tp_block_size, the expression would never overflow.

---
 net/packet/af_packet.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -3820,6 +3820,8 @@ static int packet_set_ring(struct sock *
 		rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
 		if (unlikely(rb->frames_per_block <= 0))
 			goto out;
+		if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr))
+			goto out;
 		if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
 					req->tp_frame_nr))
 			goto out;

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/sctp-listen-on-the-sock-only-when-it-s-state-is-listening-or-closed.patch queue-3.18/net-packet-fix-overflow-in-check-for-tp_frame_nr.patch queue-3.18/net-packet-fix-overflow-in-check-for-tp_reserve.patch queue-3.18/ip6mr-fix-notification-device-destruction.patch