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 57226C28EBD for ; Sun, 9 Jun 2019 16:58:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31169204EC for ; Sun, 9 Jun 2019 16:58:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099517; bh=Qo2UIqWpafIlwa/aJSTAVdXOyHN3HzwCKtuYVgnQHrc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hh9VjNSuqE52XMfKyEHv50BmpiAIWKrzo48dh5KW4JcXwu8S6k5B+bnP+fC9Gf5Lx rKuuvToSSmxeAMDQN2yOqa+wqkNrdVd50srxDTwwBfm3YIo+qwA4YJNY3bRb91FOtw Qg2NvuU/FZ8BKx0CSROuNF7tBK5bubpy0GZZfWKI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387498AbfFIQ6g (ORCPT ); Sun, 9 Jun 2019 12:58:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:33868 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387460AbfFIQ6d (ORCPT ); Sun, 9 Jun 2019 12:58:33 -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 40773206C3; Sun, 9 Jun 2019 16:58:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099512; bh=Qo2UIqWpafIlwa/aJSTAVdXOyHN3HzwCKtuYVgnQHrc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yv4JAztQPT2TZ9J+dod+ksZjSdoq+swSRMoIbStMy4u4SrFt8nDq5SOzKrAWsrsrr PlWj7MHsSiEF9Pg8hyIuRKLEi83C2uWQOV3K4BNScg3Zmvz+2CHESrS78Jv5rN5Mxj v4Npb/NlVcllZESxzkxsrkdcq3eeVh1f4NnMHSZQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Steffen Klassert , Sasha Levin Subject: [PATCH 4.4 067/241] xfrm4: Fix uninitialized memory read in _decode_session4 Date: Sun, 9 Jun 2019 18:40:09 +0200 Message-Id: <20190609164149.711754607@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190609164147.729157653@linuxfoundation.org> References: <20190609164147.729157653@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 [ 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 fddae0164b918..d9758ecdcba6a 100644 --- a/net/ipv4/xfrm4_policy.c +++ b/net/ipv4/xfrm4_policy.c @@ -108,7 +108,8 @@ 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; @@ -119,6 +120,11 @@ _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: @@ -130,7 +136,7 @@ _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]; @@ -143,7 +149,7 @@ _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]; @@ -156,7 +162,7 @@ _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]; @@ -168,7 +174,7 @@ _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]; @@ -180,7 +186,7 @@ _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])); @@ -193,7 +199,7 @@ _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; @@ -210,10 +216,6 @@ _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 inline int xfrm4_garbage_collect(struct dst_ops *ops) -- 2.20.1