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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham 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 7F2F5C282E1 for ; Wed, 24 Apr 2019 17:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D4A4218B0 for ; Wed, 24 Apr 2019 17:29:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126999; bh=B9iZMpWju9Y9ei2xE33LIsTj7fYgP4CcfWfUNxBJBhc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=G802DsrikLdVMPP/sPzpcz1ACxJxFCax2ZXHGWoCawiYt4vG9l2RQEwAO3sQK42D+ fJKcuMSEoZJBhEq16I6Rfo9OP8+mH2Npu+KIjD2FNmrBeto1GaVPWi+3dUeyEr4emq jKy1uwGtlIrFiqihoGOmiSoPtPYSgjuW4/MRiG0k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390904AbfDXR35 (ORCPT ); Wed, 24 Apr 2019 13:29:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:56168 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390892AbfDXR3y (ORCPT ); Wed, 24 Apr 2019 13:29:54 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C202B218B0; Wed, 24 Apr 2019 17:29:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126994; bh=B9iZMpWju9Y9ei2xE33LIsTj7fYgP4CcfWfUNxBJBhc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jb3nvVma+6wmKR8KvldKW3ym1ElRlZ89etZR70aVTyWwm+RzWst5UFVac5jy/padM leTSvyE/JQu3fzJWbYVvkTWuD0mrVQyncsplPDfiO2raFCThSB8/l8ZvscP77rq+MB frb1w66k/+N9X7Qnf5mqvYAV3h4uKKS5GmWhHIOo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kevin Darbyshire-Bryant , =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Subject: [PATCH 4.19 21/96] sch_cake: Make sure we can write the IP header before changing DSCP bits Date: Wed, 24 Apr 2019 19:09:26 +0200 Message-Id: <20190424170921.282123909@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170919.829037226@linuxfoundation.org> References: <20190424170919.829037226@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Toke Høiland-Jørgensen [ Upstream commit c87b4ecdbe8db27867a7b7f840291cd843406bd7 ] There is not actually any guarantee that the IP headers are valid before we access the DSCP bits of the packets. Fix this using the same approach taken in sch_dsmark. Reported-by: Kevin Darbyshire-Bryant Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_cake.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -1524,16 +1524,27 @@ static void cake_wash_diffserv(struct sk static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash) { + int wlen = skb_network_offset(skb); u8 dscp; switch (tc_skb_protocol(skb)) { case htons(ETH_P_IP): + wlen += sizeof(struct iphdr); + if (!pskb_may_pull(skb, wlen) || + skb_try_make_writable(skb, wlen)) + return 0; + dscp = ipv4_get_dsfield(ip_hdr(skb)) >> 2; if (wash && dscp) ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0); return dscp; case htons(ETH_P_IPV6): + wlen += sizeof(struct ipv6hdr); + if (!pskb_may_pull(skb, wlen) || + skb_try_make_writable(skb, wlen)) + return 0; + dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2; if (wash && dscp) ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0);