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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,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 47542C282DE for ; Thu, 23 May 2019 19:13:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 202572133D for ; Thu, 23 May 2019 19:13:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558638826; bh=bGCIwPJkbLn5Adn3ggc+NWKE25oDMPDavsVzc8He8Us=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pJHqD8AndyZLBX8Qy8UqY4HKAbtuWmVUTJDjYS/tCDRM6b2+/4YX4jEEfQsPZ2xTt MoOeCFwgrFu6pDHt8pMm3tDwpOEho+6Bk8XH593XZ/3t1d5QZ1Wr9Kz2dSyESHzf7I uxRQC3LgL7qVgZrlk7c8RcLTCUUDPqYkB7kW0YLg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388224AbfEWTNo (ORCPT ); Thu, 23 May 2019 15:13:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:47704 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388192AbfEWTNl (ORCPT ); Thu, 23 May 2019 15:13:41 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 BF90C20863; Thu, 23 May 2019 19:13:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558638820; bh=bGCIwPJkbLn5Adn3ggc+NWKE25oDMPDavsVzc8He8Us=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z3pv2pP7RpL/gNjIQgKeh5GkO19+hy8xy3hrsqNP79gcr2Trwmxgd4Sy3UZxbvDxx e8UUTdAkR8Xgg4lG2KeDcipofJSY+apvdOsR/u+rcayaLiBS9PYAyGvhSeTGkLBB8d I2IFwaPuCnA8mxWrPYDgsg8tFflgNIPED5YCE8mU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Steffen Klassert , Sasha Levin Subject: [PATCH 4.14 60/77] xfrm4: Fix uninitialized memory read in _decode_session4 Date: Thu, 23 May 2019 21:06:18 +0200 Message-Id: <20190523181728.247459342@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190523181719.982121681@linuxfoundation.org> References: <20190523181719.982121681@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 8742dc86d0c7a9628117a989c11f04a9b6b898f3 ] We currently don't reload pointers pointing into skb header after doing pskb_may_pull() in _decode_session4(). So in case pskb_may_pull() changed the pointers, we read from random memory. Fix this by putting all the needed infos on the stack, so that we don't need to access the header pointers after doing pskb_may_pull(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/ipv4/xfrm4_policy.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c index 4b586e7d56370..5952dca98e6b7 100644 --- a/net/ipv4/xfrm4_policy.c +++ b/net/ipv4/xfrm4_policy.c @@ -111,7 +111,8 @@ static void _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) { const struct iphdr *iph = ip_hdr(skb); - u8 *xprth = skb_network_header(skb) + iph->ihl * 4; + int ihl = iph->ihl; + u8 *xprth = skb_network_header(skb) + ihl * 4; struct flowi4 *fl4 = &fl->u.ip4; int oif = 0; @@ -122,6 +123,11 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) fl4->flowi4_mark = skb->mark; fl4->flowi4_oif = reverse ? skb->skb_iif : oif; + fl4->flowi4_proto = iph->protocol; + fl4->daddr = reverse ? iph->saddr : iph->daddr; + fl4->saddr = reverse ? iph->daddr : iph->saddr; + fl4->flowi4_tos = iph->tos; + if (!ip_is_fragment(iph)) { switch (iph->protocol) { case IPPROTO_UDP: @@ -133,7 +139,7 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) pskb_may_pull(skb, xprth + 4 - skb->data)) { __be16 *ports; - xprth = skb_network_header(skb) + iph->ihl * 4; + xprth = skb_network_header(skb) + ihl * 4; ports = (__be16 *)xprth; fl4->fl4_sport = ports[!!reverse]; @@ -146,7 +152,7 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) pskb_may_pull(skb, xprth + 2 - skb->data)) { u8 *icmp; - xprth = skb_network_header(skb) + iph->ihl * 4; + xprth = skb_network_header(skb) + ihl * 4; icmp = xprth; fl4->fl4_icmp_type = icmp[0]; @@ -159,7 +165,7 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) pskb_may_pull(skb, xprth + 4 - skb->data)) { __be32 *ehdr; - xprth = skb_network_header(skb) + iph->ihl * 4; + xprth = skb_network_header(skb) + ihl * 4; ehdr = (__be32 *)xprth; fl4->fl4_ipsec_spi = ehdr[0]; @@ -171,7 +177,7 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) pskb_may_pull(skb, xprth + 8 - skb->data)) { __be32 *ah_hdr; - xprth = skb_network_header(skb) + iph->ihl * 4; + xprth = skb_network_header(skb) + ihl * 4; ah_hdr = (__be32 *)xprth; fl4->fl4_ipsec_spi = ah_hdr[1]; @@ -183,7 +189,7 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) pskb_may_pull(skb, xprth + 4 - skb->data)) { __be16 *ipcomp_hdr; - xprth = skb_network_header(skb) + iph->ihl * 4; + xprth = skb_network_header(skb) + ihl * 4; ipcomp_hdr = (__be16 *)xprth; fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); @@ -196,7 +202,7 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) __be16 *greflags; __be32 *gre_hdr; - xprth = skb_network_header(skb) + iph->ihl * 4; + xprth = skb_network_header(skb) + ihl * 4; greflags = (__be16 *)xprth; gre_hdr = (__be32 *)xprth; @@ -213,10 +219,6 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) break; } } - fl4->flowi4_proto = iph->protocol; - fl4->daddr = reverse ? iph->saddr : iph->daddr; - fl4->saddr = reverse ? iph->daddr : iph->saddr; - fl4->flowi4_tos = iph->tos; } static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk, -- 2.20.1