From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2851C43219 for ; Sat, 27 Apr 2019 15:33:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 91313206C1 for ; Sat, 27 Apr 2019 15:33:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728325AbfD0Pde (ORCPT ); Sat, 27 Apr 2019 11:33:34 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60598 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726542AbfD0PPK (ORCPT ); Sat, 27 Apr 2019 11:15:10 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hKP2h-0000z5-Aq; Sat, 27 Apr 2019 16:15:07 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hKP2h-0004Ni-4m; Sat, 27 Apr 2019 16:15:07 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , syzbot+9d7405c7faa390e60b4e@syzkaller.appspotmail.com, syzbot+7d20bc3f1ddddc0f9079@syzkaller.appspotmail.com, "Sven Eckelmann" , "Simon Wunderlich" Date: Sat, 27 Apr 2019 16:13:09 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 002/202] batman-adv: Force mac header to start of data on xmit In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.66-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit 9114daa825fc3f335f9bea3313ce667090187280 upstream. The caller of ndo_start_xmit may not already have called skb_reset_mac_header. The returned value of skb_mac_header/eth_hdr therefore can be in the wrong position and even outside the current skbuff. This for example happens when the user binds to the device using a PF_PACKET-SOCK_RAW with enabled qdisc-bypass: int opt = 4; setsockopt(sock, SOL_PACKET, PACKET_QDISC_BYPASS, &opt, sizeof(opt)); Since eth_hdr is used all over the codebase, the batadv_interface_tx function must always take care of resetting it. Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") Reported-by: syzbot+9d7405c7faa390e60b4e@syzkaller.appspotmail.com Reported-by: syzbot+7d20bc3f1ddddc0f9079@syzkaller.appspotmail.com Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Ben Hutchings --- net/batman-adv/soft-interface.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -180,6 +180,8 @@ static int batadv_interface_tx(struct sk soft_iface->trans_start = jiffies; vid = batadv_get_vid(skb, 0); + + skb_reset_mac_header(skb); ethhdr = eth_hdr(skb); switch (ntohs(ethhdr->h_proto)) {