From 36ce3fbda96fdc07b67e7ef97d875f96ae68b655 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Wed, 29 Mar 2017 16:11:21 +0200 Subject: net/packet: fix overflow in check for tp_frame_nr 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. Change-Id: I3598423e621275aa1d890b80bcf9018929087d90 Signed-off-by: Andrey Konovalov Acked-by: Eric Dumazet --- net/packet/af_packet.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 838eca7cc..4264e5c01 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3672,6 +3672,8 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 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; -- cgit v1.2.3