From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:57982 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936400AbeE1KJv (ORCPT ); Mon, 28 May 2018 06:09:51 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matthias Schiffer , Sven Eckelmann , Simon Wunderlich , Sasha Levin Subject: [PATCH 3.18 095/185] batman-adv: fix header size check in batadv_dbg_arp() Date: Mon, 28 May 2018 12:02:16 +0200 Message-Id: <20180528100059.012095486@linuxfoundation.org> In-Reply-To: <20180528100050.700971285@linuxfoundation.org> References: <20180528100050.700971285@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matthias Schiffer [ Upstream commit 6f27d2c2a8c236d296201c19abb8533ec20d212b ] Checking for 0 is insufficient: when an SKB without a batadv header, but with a VLAN header is received, hdr_size will be 4, making the following code interpret the Ethernet header as a batadv header. Fixes: be1db4f6615b ("batman-adv: make the Distributed ARP Table vlan aware") Signed-off-by: Matthias Schiffer Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/distributed-arp-table.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -343,7 +343,7 @@ static void batadv_dbg_arp(struct batadv batadv_arp_hw_src(skb, hdr_size), &ip_src, batadv_arp_hw_dst(skb, hdr_size), &ip_dst); - if (hdr_size == 0) + if (hdr_size < sizeof(struct batadv_unicast_packet)) return; unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;