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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 B97E9C71122 for ; Sun, 14 Oct 2018 15:37:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 87BC120645 for ; Sun, 14 Oct 2018 15:37:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 87BC120645 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk 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 S1728824AbeJNXTD (ORCPT ); Sun, 14 Oct 2018 19:19:03 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36746 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728153AbeJNXTD (ORCPT ); Sun, 14 Oct 2018 19:19:03 -0400 Received: from [2a02:8011:400e:2:cbab:f00:c93f:614] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1gBiM3-0004cf-60; Sun, 14 Oct 2018 16:30:55 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gBiLS-0000Ko-Ek; Sun, 14 Oct 2018 16:30:18 +0100 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, "David S. Miller" , "Eric Dumazet" , "syzbot" , "Yuchung Cheng" Date: Sun, 14 Oct 2018 16:25:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 142/366] tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:cbab:f00:c93f:614 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.60-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 7212303268918b9a203aebeacfdbd83b5e87b20d upstream. syzbot/KMSAN reported an uninit-value in tcp_parse_options() [1] I believe this was caused by a TCP_MD5SIG being set on live flow. This is highly unexpected, since TCP option space is limited. For instance, presence of TCP MD5 option automatically disables TCP TimeStamp option at SYN/SYNACK time, which we can not do once flow has been established. Really, adding/deleting an MD5 key only makes sense on sockets in CLOSE or LISTEN state. [1] BUG: KMSAN: uninit-value in tcp_parse_options+0xd74/0x1a30 net/ipv4/tcp_input.c:3720 CPU: 1 PID: 6177 Comm: syzkaller192004 Not tainted 4.16.0+ #83 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 tcp_parse_options+0xd74/0x1a30 net/ipv4/tcp_input.c:3720 tcp_fast_parse_options net/ipv4/tcp_input.c:3858 [inline] tcp_validate_incoming+0x4f1/0x2790 net/ipv4/tcp_input.c:5184 tcp_rcv_established+0xf60/0x2bb0 net/ipv4/tcp_input.c:5453 tcp_v4_do_rcv+0x6cd/0xd90 net/ipv4/tcp_ipv4.c:1469 sk_backlog_rcv include/net/sock.h:908 [inline] __release_sock+0x2d6/0x680 net/core/sock.c:2271 release_sock+0x97/0x2a0 net/core/sock.c:2786 tcp_sendmsg+0xd6/0x100 net/ipv4/tcp.c:1464 inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] SYSC_sendto+0x6c3/0x7e0 net/socket.c:1747 SyS_sendto+0x8a/0xb0 net/socket.c:1715 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x448fe9 RSP: 002b:00007fd472c64d38 EFLAGS: 00000216 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000006e5a30 RCX: 0000000000448fe9 RDX: 000000000000029f RSI: 0000000020a88f88 RDI: 0000000000000004 RBP: 00000000006e5a34 R08: 0000000020e68000 R09: 0000000000000010 R10: 00000000200007fd R11: 0000000000000216 R12: 0000000000000000 R13: 00007fff074899ef R14: 00007fd472c659c0 R15: 0000000000000009 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc_node mm/slub.c:2737 [inline] __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:984 [inline] tcp_send_ack+0x18c/0x910 net/ipv4/tcp_output.c:3624 __tcp_ack_snd_check net/ipv4/tcp_input.c:5040 [inline] tcp_ack_snd_check net/ipv4/tcp_input.c:5053 [inline] tcp_rcv_established+0x2103/0x2bb0 net/ipv4/tcp_input.c:5469 tcp_v4_do_rcv+0x6cd/0xd90 net/ipv4/tcp_ipv4.c:1469 sk_backlog_rcv include/net/sock.h:908 [inline] __release_sock+0x2d6/0x680 net/core/sock.c:2271 release_sock+0x97/0x2a0 net/core/sock.c:2786 tcp_sendmsg+0xd6/0x100 net/ipv4/tcp.c:1464 inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] SYSC_sendto+0x6c3/0x7e0 net/socket.c:1747 SyS_sendto+0x8a/0xb0 net/socket.c:1715 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Fixes: cfb6eeb4c860 ("[TCP]: MD5 Signature Option (RFC2385) support.") Signed-off-by: Eric Dumazet Reported-by: syzbot Acked-by: Yuchung Cheng Signed-off-by: David S. Miller [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- net/ipv4/tcp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2683,8 +2683,10 @@ static int do_tcp_setsockopt(struct sock #ifdef CONFIG_TCP_MD5SIG case TCP_MD5SIG: - /* Read the IP->Key mappings from userspace */ - err = tp->af_specific->md5_parse(sk, optval, optlen); + if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) + err = tp->af_specific->md5_parse(sk, optval, optlen); + else + err = -EINVAL; break; #endif case TCP_USER_TIMEOUT: