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 E21E7C10F11 for ; Wed, 24 Apr 2019 17:22:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD40520675 for ; Wed, 24 Apr 2019 17:22:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126539; bh=Iipc3dRx1CDZCpkc6w+7RdtCKlUAQm9/Hwze5cPwzxA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JmqLXPWgLR20fKpRSqLmdpUR5sBOeMoNjEGxMb7kQXaDHwQzPuJb1LbLV3GpwFrJU GubKIdX2l41RnmDSi9XWfAU064+TG6nFRvAP/1FIlT0fyK/iuvfdsdlgFxT1Ciciin Rlv7bUc6iqTeUP1BiFB8qMpwGvDNKI66kj4z3Dtw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389535AbfDXRWS (ORCPT ); Wed, 24 Apr 2019 13:22:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:47808 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389130AbfDXRWQ (ORCPT ); Wed, 24 Apr 2019 13:22:16 -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 3C90220675; Wed, 24 Apr 2019 17:22:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126534; bh=Iipc3dRx1CDZCpkc6w+7RdtCKlUAQm9/Hwze5cPwzxA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TXFJeW8WRbNSW7ovps/yH3mU/CKZmd2Euxagq65Veej7xdEnOOENAH56SpCugySPI ulsNg4riFVOi/biXtAHIP68zRc4KWVw4CfIIm3kr6Rc2LDdIKCrjEbvCPYq8YQ/aV3 ZJjba9Yh/21wrIgrCvsp1MxHVBu8kZLSUGrrrsTs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lorenzo Bianconi , "David S. Miller" Subject: [PATCH 4.4 140/168] net: fou: do not use guehdr after iptunnel_pull_offloads in gue_udp_recv Date: Wed, 24 Apr 2019 19:09:44 +0200 Message-Id: <20190424170931.535386004@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170923.452349382@linuxfoundation.org> References: <20190424170923.452349382@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: Lorenzo Bianconi [ Upstream commit 988dc4a9a3b66be75b30405a5494faf0dc7cffb6 ] gue tunnels run iptunnel_pull_offloads on received skbs. This can determine a possible use-after-free accessing guehdr pointer since the packet will be 'uncloned' running pskb_expand_head if it is a cloned gso skb (e.g if the packet has been sent though a veth device) Fixes: a09a4c8dd1ec ("tunnels: Remove encapsulation offloads on decap") Signed-off-by: Lorenzo Bianconi Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/fou.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -116,6 +116,7 @@ static int gue_udp_recv(struct sock *sk, struct guehdr *guehdr; void *data; u16 doffset = 0; + u8 proto_ctype; if (!fou) return 1; @@ -173,13 +174,14 @@ static int gue_udp_recv(struct sock *sk, if (unlikely(guehdr->control)) return gue_control_message(skb, guehdr); + proto_ctype = guehdr->proto_ctype; __skb_pull(skb, sizeof(struct udphdr) + hdrlen); skb_reset_transport_header(skb); if (iptunnel_pull_offloads(skb)) goto drop; - return -guehdr->proto_ctype; + return -proto_ctype; drop: kfree_skb(skb);