Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754741AbeAKJaX (ORCPT + 1 other); Thu, 11 Jan 2018 04:30:23 -0500 Received: from mail-qk0-f194.google.com ([209.85.220.194]:33294 "EHLO mail-qk0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750752AbeAKJaS (ORCPT ); Thu, 11 Jan 2018 04:30:18 -0500 X-Google-Smtp-Source: ACJfBouRSmqqlGDfoLxSUsxW9mjKiKGuXcGRioyi9P8XAVrAeuc9PPPS25/kFEJSMeSNO4gmOIFfgQmQMWM+QV80Iqc= MIME-Version: 1.0 In-Reply-To: <94eb2c0bd5648167ae0562700241@google.com> References: <089e08259d2851dbad05626f6c36@google.com> <94eb2c0bd5648167ae0562700241@google.com> From: Xin Long Date: Thu, 11 Jan 2018 17:30:17 +0800 Message-ID: Subject: Re: general protection fault in sctp_v6_get_dst To: syzbot Cc: davem , LKML , linux-sctp@vger.kernel.org, network dev , Neil Horman , syzkaller-bugs@googlegroups.com, Vlad Yasevich Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Thu, Jan 11, 2018 at 2:15 AM, syzbot wrote: > syzkaller has found reproducer for the following crash on > 61ad64080e039dce99a7f8d89b729bbea995e2f7 > git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+7b7b518b1228d2743963@syzkaller.appspotmail.com > It will help syzbot understand when the bug is fixed. > > device lo entered promiscuous mode > kasan: CONFIG_KASAN_INLINE enabled > kasan: GPF could be caused by NULL-ptr deref or user memory access > general protection fault: 0000 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 0 PID: 3506 Comm: syzkaller968983 Not tainted 4.15.0-rc7+ #181 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline] > RIP: 0010:sctp_v6_get_dst+0x59e/0x1c60 net/sctp/ipv6.c:271 > RSP: 0018:ffff8801db205e20 EFLAGS: 00010206 > RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8512e05b > RDX: 000000000000000f RSI: 0000000067cf608c RDI: ffff8801db22376c > RBP: ffff8801db206190 R08: 1ffff1003b640b05 R09: 0000000000000002 > R10: ffff8801db205cf0 R11: ffffffff8512e008 R12: ffff8801bf884db0 > R13: 000000000000204e R14: ffff8801bfe3e680 R15: ffff8801bf884d80 > FS: 00007f122e219700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000020aaff09 CR3: 00000001bfdf0005 CR4: 00000000001606f0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > sctp_transport_route+0xa8/0x430 net/sctp/transport.c:293 > sctp_assoc_add_peer+0x4fe/0x1190 net/sctp/associola.c:655 > sctp_process_init+0x119/0x2440 net/sctp/sm_make_chunk.c:2341 > sctp_sf_do_5_1B_init+0x8c9/0xe80 net/sctp/sm_statefuns.c:414 > sctp_do_sm+0x192/0x6ed0 net/sctp/sm_sideeffect.c:1178 > sctp_endpoint_bh_rcv+0x379/0x8f0 net/sctp/endpointola.c:456 > sctp_inq_push+0x23b/0x300 net/sctp/inqueue.c:95 > sctp_rcv+0x29f3/0x35c0 net/sctp/input.c:267 > sctp6_rcv+0x15/0x30 net/sctp/ipv6.c:1006 > ip6_input_finish+0x37e/0x17a0 net/ipv6/ip6_input.c:284 > NF_HOOK include/linux/netfilter.h:288 [inline] > ip6_input+0xdb/0x560 net/ipv6/ip6_input.c:327 > dst_input include/net/dst.h:449 [inline] > ip6_rcv_finish+0x1a9/0x7a0 net/ipv6/ip6_input.c:71 > NF_HOOK include/linux/netfilter.h:288 [inline] > ipv6_rcv+0xf37/0x1fa0 net/ipv6/ip6_input.c:208 > __netif_receive_skb_core+0x1a41/0x3460 net/core/dev.c:4538 > __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4603 > process_backlog+0x203/0x740 net/core/dev.c:5283 > napi_poll net/core/dev.c:5681 [inline] > net_rx_action+0x792/0x1910 net/core/dev.c:5747 > __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 > do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1133 > > do_softirq.part.21+0x14d/0x190 kernel/softirq.c:329 > do_softirq kernel/softirq.c:177 [inline] > __local_bh_enable_ip+0x1ee/0x230 kernel/softirq.c:182 > local_bh_enable include/linux/bottom_half.h:32 [inline] > rcu_read_unlock_bh include/linux/rcupdate.h:727 [inline] > ip6_finish_output2+0xba0/0x23a0 net/ipv6/ip6_output.c:121 > ip6_finish_output+0x698/0xaf0 net/ipv6/ip6_output.c:154 > NF_HOOK_COND include/linux/netfilter.h:277 [inline] > ip6_output+0x1eb/0x840 net/ipv6/ip6_output.c:171 > dst_output include/net/dst.h:443 [inline] > NF_HOOK include/linux/netfilter.h:288 [inline] > ip6_xmit+0xd84/0x2090 net/ipv6/ip6_output.c:277 > sctp_v6_xmit+0x438/0x630 net/sctp/ipv6.c:225 > sctp_packet_transmit+0x225e/0x3750 net/sctp/output.c:638 > sctp_outq_flush+0xabb/0x4060 net/sctp/outqueue.c:911 > sctp_outq_uncork+0x5a/0x70 net/sctp/outqueue.c:776 > sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1807 [inline] > sctp_side_effects net/sctp/sm_sideeffect.c:1210 [inline] > sctp_do_sm+0x4e0/0x6ed0 net/sctp/sm_sideeffect.c:1181 > sctp_primitive_ASSOCIATE+0x9d/0xd0 net/sctp/primitive.c:88 > sctp_sendmsg+0x1d2e/0x33f0 net/sctp/socket.c:2018 > inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764 > sock_sendmsg_nosec net/socket.c:628 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:638 > SYSC_sendto+0x361/0x5c0 net/socket.c:1719 > SyS_sendto+0x40/0x50 net/socket.c:1687 > entry_SYSCALL_64_fastpath+0x23/0x9a > RIP: 0033:0x4456c9 > RSP: 002b:00007f122e218d98 EFLAGS: 00000212 ORIG_RAX: 000000000000002c > RAX: ffffffffffffffda RBX: 00000000006dac3c RCX: 00000000004456c9 > RDX: 0000000000000001 RSI: 0000000020aaff09 RDI: 0000000000000007 > RBP: 0000000000000000 R08: 0000000020abf000 R09: 000000000000001c > R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006dac38 > R13: 0000800000000001 R14: 0100000000000000 R15: 0000000000000008 > Code: 10 00 00 e8 e5 3d 5d fc 48 8b 85 e8 fc ff ff 48 83 c0 78 48 89 c2 48 > 89 85 c0 fc ff ff 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f > 85 e9 15 00 00 48 8b 85 e8 fc ff ff 4c 8d b5 30 > RIP: __read_once_size include/linux/compiler.h:183 [inline] RSP: > ffff8801db205e20 > RIP: sctp_v6_get_dst+0x59e/0x1c60 net/sctp/ipv6.c:271 RSP: ffff8801db205e20 > ---[ end trace 63ac71b302800ef4 ]--- > v4 socket shouldn't have been allowed to bind v6 address, even it's v4mapped. index de1087d..3595097 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -353,15 +353,14 @@ static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt, if (len < sizeof (struct sockaddr)) return NULL; + if (!opt->pf->af_supported(addr->sa.sa_family, opt)) + return NULL; + /* V4 mapped address are really of AF_INET family */ if (addr->sa.sa_family == AF_INET6 && ipv6_addr_v4mapped(&addr->v6.sin6_addr)) { if (!opt->pf->af_supported(AF_INET, opt)) return NULL; - } else { - /* Does this PF support this AF? */ - if (!opt->pf->af_supported(addr->sa.sa_family, opt)) - return NULL; }