From dfb157d7a154be08cdaa8119e96cac12c491e39f Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Wed, 29 Mar 2017 16:11:21 +0200 Subject: [PATCH] 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: I183d9adb8b90010f408b5e1d0785aa06814f4348 Signed-off-by: Andrey Konovalov Acked-by: Eric Dumazet Signed-off-by: David S. Miller Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Git-commit: 8f8d28e4d6d815a391285e121c3a53a0b6cb9e7b Signed-off-by: Dennis Cagle --- 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 f223d1c80ccf..d564572adf80 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -4127,6 +4127,8 @@ 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;