From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1511654-1518326170-2-2254610280147216227 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES enca, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='uk', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518326170; b=GfrpjEnIpvA00Tq9kkseJjRpPxDfilV1F0q7HBazAvdMYZw 2tWPjjZTm0EZhXvSBdNulnKDQgl57YM7Uxpsx05VxDbs8DQNn2W+fymcazGjjAFj JUtBmX6oZzncxU+6BJ3R1Z24NxdHP80bZEahjCL8Q8Bhn7VN/V7diwX0rmRoDFXO COrlZ4UHJOEB+BQzjVWLESRFBzG+a7Gd9vf+5Xe1g5Fcebz0niddt3e6fI17404W yIK6HkVFPW3ECmfn2rkLAFEw3TgwvPOLjcc0zE2phKbaynqlusECGEkgjoKGrT6g 8fGUqH2YqUfNlU59vBwmG4kJ9Y/dZ7ZPANvuMBg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:content-transfer-encoding :mime-version:from:to:cc:date:message-id:subject:in-reply-to :sender:list-id; s=arctest; t=1518326170; bh=ETXYDrtvBE2DQ7YwYnw KZ/opPjeCWEfO0PAis5lzuPE=; b=ftLgbtuudEhbap8po2t1m4yPVes8DPqaH7F tpY1jfU2eoFpodH+gu4hhkg5SY6sFfhb1PeOR44h5f7XgWSnNkhVr+11mpFhslHj O6cZMfgqb2SLQ8Xre5cgGDaMSHbw+D1liWRwal2GCxAAr466WbFj+phxDqymqJbx yVM/AYqmTrax4p8n70WQD/T4G4xFhBbHCjJNc+Dbpv16LpGH04K7i5f1VF4EeQvT GfxWqA/pe7D+Vy1bA2bWL9pNXimHeIHNSxCioGetmdCu3CpY8Fm9ny6apWJw4fOx xUl2goth5kGd4/Ph29FaGoex8htLgqA6YYEgngSjJkKtAIq2g/w== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754023AbeBKFOW (ORCPT ); Sun, 11 Feb 2018 00:14:22 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41364 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752586AbeBKEdl (ORCPT ); Sat, 10 Feb 2018 23:33:41 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Eric Dumazet" , "Pablo Neira Ayuso" , "Denys Fedoryshchenko" Date: Sun, 11 Feb 2018 04:20:06 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 66/79] netfilter: xt_TCPMSS: add more sanity tests on tcph->doff In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 3.2.99-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 2638fd0f92d4397884fd991d8f4925cb3f081901 upstream. Denys provided an awesome KASAN report pointing to an use after free in xt_TCPMSS I have provided three patches to fix this issue, either in xt_TCPMSS or in xt_tcpudp.c. It seems xt_TCPMSS patch has the smallest possible impact. Signed-off-by: Eric Dumazet Reported-by: Denys Fedoryshchenko Signed-off-by: Pablo Neira Ayuso Signed-off-by: Ben Hutchings --- net/netfilter/xt_TCPMSS.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/net/netfilter/xt_TCPMSS.c +++ b/net/netfilter/xt_TCPMSS.c @@ -71,7 +71,7 @@ tcpmss_mangle_packet(struct sk_buff *skb tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff); tcp_hdrlen = tcph->doff * 4; - if (len < tcp_hdrlen) + if (len < tcp_hdrlen || tcp_hdrlen < sizeof(struct tcphdr)) return -1; if (info->mss == XT_TCPMSS_CLAMP_PMTU) { @@ -122,6 +122,10 @@ tcpmss_mangle_packet(struct sk_buff *skb if (len > tcp_hdrlen) return 0; + /* tcph->doff has 4 bits, do not wrap it to 0 */ + if (tcp_hdrlen >= 15 * 4) + return 0; + /* * MSS Option not found ?! add it.. */