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,URIBL_BLOCKED,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 C10D4C282C2 for ; Thu, 7 Feb 2019 11:45:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 843632080A for ; Thu, 7 Feb 2019 11:45:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549539900; bh=m2REHVcuVdu4YuIakkijT1jPpuXGl2KrH1+tyXxk6m0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HJmlGfxEpQ2zTA7nTQR6LME9nhB5GSPXYfewoGyW12uO4ImHVfY1bQfn2UwSmFXec AnMqyn+0hEWTpp6cwHANKoSlZy9fAh0mMoN91FVE3g2QGgbiQfhcZGTrqYLznyE/04 3hAkxbN/nCOg7sA4ExclUtXHWrPj+wWu8nLnGvLg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727305AbfBGLo7 (ORCPT ); Thu, 7 Feb 2019 06:44:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:33340 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727338AbfBGLnK (ORCPT ); Thu, 7 Feb 2019 06:43:10 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 B72B021904; Thu, 7 Feb 2019 11:43:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549539790; bh=m2REHVcuVdu4YuIakkijT1jPpuXGl2KrH1+tyXxk6m0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1klxN4Y6kLFQLci2bEFf9nvavKlrHDxCHY0WqrDDHPWDTqTut+Hh4rgzBz4xVSQ/w 92zRpNlgHWok4YaB3nTSH26T02U0i7PpeUbFffo5En7IpaJ29ZWGnJcrkMuZE6Uq1p Wy7EdAPybR2wu6DC5usMFNvcb0MKFpzknQjAGsyA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Oskolkov , Eric Dumazet , Florian Westphal , "David S. Miller" , Mao Wenan , Ben Hutchings Subject: [PATCH 4.4 24/34] ipv6: defrag: drop non-last frags smaller than min mtu Date: Thu, 7 Feb 2019 12:42:06 +0100 Message-Id: <20190207113026.506757266@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190207113025.552605181@linuxfoundation.org> References: <20190207113025.552605181@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal commit 0ed4229b08c13c84a3c301a08defdc9e7f4467e6 upstream. don't bother with pathological cases, they only waste cycles. IPv6 requires a minimum MTU of 1280 so we should never see fragments smaller than this (except last frag). v3: don't use awkward "-offset + len" v2: drop IPv4 part, which added same check w. IPV4_MIN_MTU (68). There were concerns that there could be even smaller frags generated by intermediate nodes, e.g. on radio networks. Cc: Peter Oskolkov Cc: Eric Dumazet Signed-off-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Mao Wenan [bwh: Backported to 4.4: In nf_ct_frag6_gather() use clone instead of skb, and goto ret_orig in case of error] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- net/ipv6/netfilter/nf_conntrack_reasm.c | 4 ++++ net/ipv6/reassembly.c | 4 ++++ 2 files changed, 8 insertions(+) --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -574,6 +574,10 @@ struct sk_buff *nf_ct_frag6_gather(struc hdr = ipv6_hdr(clone); fhdr = (struct frag_hdr *)skb_transport_header(clone); + if (clone->len - skb_network_offset(clone) < IPV6_MIN_MTU && + fhdr->frag_off & htons(IP6_MF)) + goto ret_orig; + skb_orphan(skb); fq = fq_find(net, fhdr->identification, user, hdr, skb->dev ? skb->dev->ifindex : 0); --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -515,6 +515,10 @@ static int ipv6_frag_rcv(struct sk_buff return 1; } + if (skb->len - skb_network_offset(skb) < IPV6_MIN_MTU && + fhdr->frag_off & htons(IP6_MF)) + goto fail_hdr; + iif = skb->dev ? skb->dev->ifindex : 0; fq = fq_find(net, fhdr->identification, hdr, iif); if (fq) {