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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 B16A4ECDFB8 for ; Fri, 20 Jul 2018 12:48:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 761C320652 for ; Fri, 20 Jul 2018 12:48:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 761C320652 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390529AbeGTNgn (ORCPT ); Fri, 20 Jul 2018 09:36:43 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:58498 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390387AbeGTNgm (ORCPT ); Fri, 20 Jul 2018 09:36:42 -0400 Received: from localhost (LFbn-1-12238-233.w90-92.abo.wanadoo.fr [90.92.53.233]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 2AD64D62; Fri, 20 Jul 2018 12:38:50 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , John Sperbeck , Florian Westphal , Eric Dumazet , syzbot , Pablo Neira Ayuso Subject: [PATCH 4.17 074/101] netfilter: ipv6: nf_defrag: drop skb dst before queueing Date: Fri, 20 Jul 2018 14:14:20 +0200 Message-Id: <20180720121426.441554275@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180720121422.837870592@linuxfoundation.org> References: <20180720121422.837870592@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal commit 84379c9afe011020e797e3f50a662b08a6355dcf upstream. Eric Dumazet reports: Here is a reproducer of an annoying bug detected by syzkaller on our production kernel [..] ./b78305423 enable_conntrack Then : sleep 60 dmesg | tail -10 [ 171.599093] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 181.631024] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 191.687076] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 201.703037] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 211.711072] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 221.959070] unregister_netdevice: waiting for lo to become free. Usage count = 2 Reproducer sends ipv6 fragment that hits nfct defrag via LOCAL_OUT hook. skb gets queued until frag timer expiry -- 1 minute. Normally nf_conntrack_reasm gets called during prerouting, so skb has no dst yet which might explain why this wasn't spotted earlier. Reported-by: Eric Dumazet Reported-by: John Sperbeck Signed-off-by: Florian Westphal Tested-by: Eric Dumazet Reported-by: syzbot Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/ipv6/netfilter/nf_conntrack_reasm.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -585,6 +585,8 @@ int nf_ct_frag6_gather(struct net *net, fq->q.meat == fq->q.len && nf_ct_frag6_reasm(fq, skb, dev)) ret = 0; + else + skb_dst_drop(skb); out_unlock: spin_unlock_bh(&fq->q.lock);