From patchwork Mon Mar 11 08:29:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miaohe Lin X-Patchwork-Id: 1054212 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44HrrQ1TDTz9s4Y for ; Mon, 11 Mar 2019 19:29:58 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726875AbfCKI3w (ORCPT ); Mon, 11 Mar 2019 04:29:52 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:4666 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725831AbfCKI3w (ORCPT ); Mon, 11 Mar 2019 04:29:52 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 10505851703A1F03DFF0; Mon, 11 Mar 2019 16:29:50 +0800 (CST) Received: from [127.0.0.1] (10.184.189.20) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.408.0; Mon, 11 Mar 2019 16:29:41 +0800 To: , , , , CC: Mingfangsen From: linmiaohe Subject: [PATCH net] net: sit: fix UBSAN Undefined behaviour in check_6rd Message-ID: <694fb074-53a3-af60-6561-57c022445a48@huawei.com> Date: Mon, 11 Mar 2019 16:29:32 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 Content-Language: en-US X-Originating-IP: [10.184.189.20] X-CFilter-Loop: Reflected Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Miaohe Lin In func check_6rd,tunnel->ip6rd.relay_prefixlen may equal to 32,so UBSAN complain about it. UBSAN: Undefined behaviour in net/ipv6/sit.c:781:47 shift exponent 32 is too large for 32-bit type 'unsigned int' CPU: 6 PID: 20036 Comm: syz-executor.0 Not tainted 4.19.27 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xca/0x13e lib/dump_stack.c:113 ubsan_epilogue+0xe/0x81 lib/ubsan.c:159 __ubsan_handle_shift_out_of_bounds+0x293/0x2e8 lib/ubsan.c:425 check_6rd.constprop.9+0x433/0x4e0 net/ipv6/sit.c:781 try_6rd net/ipv6/sit.c:806 [inline] ipip6_tunnel_xmit net/ipv6/sit.c:866 [inline] sit_tunnel_xmit+0x141c/0x2720 net/ipv6/sit.c:1033 __netdev_start_xmit include/linux/netdevice.h:4300 [inline] netdev_start_xmit include/linux/netdevice.h:4309 [inline] xmit_one net/core/dev.c:3243 [inline] dev_hard_start_xmit+0x17c/0x780 net/core/dev.c:3259 __dev_queue_xmit+0x1656/0x2500 net/core/dev.c:3829 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0xa36/0x2290 net/ipv6/ip6_output.c:120 ip6_finish_output+0x3e7/0xa20 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x1e2/0x720 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] ip6_local_out+0x99/0x170 net/ipv6/output_core.c:176 ip6_send_skb+0x9d/0x2f0 net/ipv6/ip6_output.c:1697 ip6_push_pending_frames+0xc0/0x100 net/ipv6/ip6_output.c:1717 rawv6_push_pending_frames net/ipv6/raw.c:616 [inline] rawv6_sendmsg+0x2435/0x3530 net/ipv6/raw.c:946 inet_sendmsg+0xf8/0x5c0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xc8/0x110 net/socket.c:631 ___sys_sendmsg+0x6cf/0x890 net/socket.c:2114 __sys_sendmsg+0xf0/0x1b0 net/socket.c:2152 do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: linmiaohe --- net/ipv6/sit.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index 09e440e8dfae..07e21a82ce4c 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -778,8 +778,9 @@ static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, pbw0 = tunnel->ip6rd.prefixlen >> 5; pbi0 = tunnel->ip6rd.prefixlen & 0x1f; - d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> - tunnel->ip6rd.relay_prefixlen; + d = tunnel->ip6rd.relay_prefixlen < 32 ? + (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> + tunnel->ip6rd.relay_prefixlen : 0; pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; if (pbi1 > 0)