From 086e1cbcc95981901a21a5b43b62f817319f3d42 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov <andreyknvl@google.com> Date: Wed, 29 Mar 2017 16:11:21 +0200 Subject: [PATCH] net/packet: fix overflow in check for tp_frame_nr [ 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. Bug: 36725304 Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Change-Id: I753f144d95b7390afb692c98f0bcf7f127471f22 --- 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 2f2a68f25145..3faaf3180066 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3820,6 +3820,8 @@ 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; -- GitLab