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=-6.1 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 ED0B9C32788 for ; Thu, 11 Oct 2018 15:36:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3F702075C for ; Thu, 11 Oct 2018 15:36:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="PPCdUxWH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B3F702075C 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 S1728592AbeJKXDm (ORCPT ); Thu, 11 Oct 2018 19:03:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:57822 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726562AbeJKXDk (ORCPT ); Thu, 11 Oct 2018 19:03:40 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (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 4409C2087A; Thu, 11 Oct 2018 15:35:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539272158; bh=sT3zZ6fbgUp2uKX8qCgtHfUKp/SG7ZZxBkyQN1Kq2zk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PPCdUxWHjibF6MHmRSB+NEaDdEeGEQQCO0dVaqENpr3YlcDK10avSCGyxwIOGILPK N4iU3xJJkMC0enLLAeZn84H2DSBfXffemkvK8GBnfJQq1GGhaKisK1d9Y8x+1L3NYc Ezgm4eRoUIGT88F8arFGIzMdxFey7TQ7eLSk+0zg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot , "David S. Miller" Subject: [PATCH 3.18 010/120] ipv6: fix possible use-after-free in ip6_xmit() Date: Thu, 11 Oct 2018 17:33:11 +0200 Message-Id: <20181011152549.957231822@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181011152549.500488630@linuxfoundation.org> References: <20181011152549.500488630@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit bbd6528d28c1b8e80832b3b018ec402b6f5c3215 ] In the unlikely case ip6_xmit() has to call skb_realloc_headroom(), we need to call skb_set_owner_w() before consuming original skb, otherwise we risk a use-after-free. Bring IPv6 in line with what we do in IPv4 to fix this. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ip6_output.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -183,9 +183,10 @@ int ip6_xmit(struct sock *sk, struct sk_ kfree_skb(skb); return -ENOBUFS; } + if (skb->sk) + skb_set_owner_w(skb2, skb->sk); consume_skb(skb); skb = skb2; - skb_set_owner_w(skb, sk); } if (opt->opt_flen) ipv6_push_frag_opts(skb, opt, &proto);