From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751460AbcEIHSK (ORCPT ); Mon, 9 May 2016 03:18:10 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54912 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750934AbcEIHSG (ORCPT ); Mon, 9 May 2016 03:18:06 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sven Eckelmann , Marek Lindner , Antonio Quartulli Subject: [PATCH 3.14 12/23] batman-adv: Check skb size before using encapsulated ETH+VLAN header Date: Mon, 9 May 2016 09:17:32 +0200 Message-Id: <20160509071647.391127442@linuxfoundation.org> X-Mailer: git-send-email 2.8.2 In-Reply-To: <20160509071646.726412064@linuxfoundation.org> References: <20160509071646.726412064@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit c78296665c3d81f040117432ab9e1cb125521b0c upstream. The encapsulated ethernet and VLAN header may be outside the received ethernet frame. Thus the skb buffer size has to be checked before it can be parsed to find out if it encapsulates another batman-adv packet. Fixes: 420193573f11 ("batman-adv: softif bridge loop avoidance") Signed-off-by: Sven Eckelmann Signed-off-by: Marek Lindner Signed-off-by: Antonio Quartulli Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/soft-interface.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -356,11 +356,17 @@ void batadv_interface_rx(struct net_devi */ nf_reset(skb); + if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) + goto dropped; + vid = batadv_get_vid(skb, 0); ethhdr = eth_hdr(skb); switch (ntohs(ethhdr->h_proto)) { case ETH_P_8021Q: + if (!pskb_may_pull(skb, VLAN_ETH_HLEN)) + goto dropped; + vhdr = (struct vlan_ethhdr *)skb->data; if (vhdr->h_vlan_encapsulated_proto != ethertype) @@ -372,8 +378,6 @@ void batadv_interface_rx(struct net_devi } /* skb->dev & skb->pkt_type are set here */ - if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) - goto dropped; skb->protocol = eth_type_trans(skb, soft_iface); /* should not be necessary anymore as we use skb_pull_rcsum()