Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751388AbeACU4D (ORCPT + 1 other); Wed, 3 Jan 2018 15:56:03 -0500 Received: from forward3o.cmail.yandex.net ([37.9.109.247]:55513 "EHLO forward3o.cmail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750873AbeACU4B (ORCPT ); Wed, 3 Jan 2018 15:56:01 -0500 Authentication-Results: mxback10g.mail.yandex.net; dkim=pass header.i=@yandex.com.tr From: Ozgur Envelope-From: okaratas@yandex.com.tr To: Cong Wang , syzbot Cc: David Miller , Alexey Kuznetsov , LKML , Linux Kernel Network Developers , "syzkaller-bugs@googlegroups.com" , Hideaki YOSHIFUJI , "avejwatson@fb.com" , "ilyal@mellanox.com" , "aviadye@mellanox.com" In-Reply-To: References: <001a113ed0fc75c8770561d3de8c@google.com> Subject: Re: KASAN: slab-out-of-bounds Write in tcp_v6_syn_recv_sock MIME-Version: 1.0 Message-Id: <681471515012954@web19j.yandex.ru> X-Mailer: Yamail [ http://yandex.ru ] 5.0 Date: Wed, 03 Jan 2018 23:55:54 +0300 Content-Transfer-Encoding: 8bit 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: 03.01.2018, 21:57, "Cong Wang" : > On Tue, Jan 2, 2018 at 3:58 PM, syzbot > wrote: >>  Hello, >> >>  syzkaller hit the following crash on >>  61233580f1f33c50e159c50e24d80ffd2ba2e06b >>  git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.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+6dc95bddc6976b800b0b@syzkaller.appspotmail.com >>  It will help syzbot understand when the bug is fixed. See footer for >>  details. >>  If you forward the report, please keep this part and the footer. >> >>  TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending >>  cookies. Check SNMP counters. >>  ================================================================== >>  BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:344 [inline] >>  BUG: KASAN: slab-out-of-bounds in tcp_v6_syn_recv_sock+0x628/0x23a0 >>  net/ipv6/tcp_ipv6.c:1144 >>  Write of size 160 at addr ffff8801cbdd7460 by task syzkaller545407/3196 >> >>  CPU: 1 PID: 3196 Comm: syzkaller545407 Not tainted 4.15.0-rc5+ #241 >>  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+0x194/0x257 lib/dump_stack.c:53 >>   print_address_description+0x73/0x250 mm/kasan/report.c:252 >>   kasan_report_error mm/kasan/report.c:351 [inline] >>   kasan_report+0x25b/0x340 mm/kasan/report.c:409 >>   check_memory_region_inline mm/kasan/kasan.c:260 [inline] >>   check_memory_region+0x137/0x190 mm/kasan/kasan.c:267 >>   memcpy+0x37/0x50 mm/kasan/kasan.c:303 >>   memcpy include/linux/string.h:344 [inline] >>   tcp_v6_syn_recv_sock+0x628/0x23a0 net/ipv6/tcp_ipv6.c:1144 > > tls_init() changes sk->sk_prot from IPv6 to IPv4, which leads > to this bug. I guess IPv6 is not supported for TLS? If so, need > a check on proto in tls_init()... Hello, I think IPv6 supports with TLS. There was a previously posted commit by Mellanox: https://patchwork.ozlabs.org/patch/801530/ Ozgur >>   tcp_get_cookie_sock+0x102/0x540 net/ipv4/syncookies.c:213 >>   cookie_v6_check+0x177d/0x2160 net/ipv6/syncookies.c:255 >>   tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1008 [inline] >>   tcp_v6_do_rcv+0xe4d/0x11c0 net/ipv6/tcp_ipv6.c:1316 >>   tcp_v6_rcv+0x22ee/0x2b40 net/ipv6/tcp_ipv6.c:1510 >>   ip6_input_finish+0x36f/0x1700 net/ipv6/ip6_input.c:284 >>   NF_HOOK include/linux/netfilter.h:250 [inline] >>   ip6_input+0xe9/0x560 net/ipv6/ip6_input.c:327 >>   dst_input include/net/dst.h:466 [inline] >>   ip6_rcv_finish+0x1a9/0x7a0 net/ipv6/ip6_input.c:71 >>   NF_HOOK include/linux/netfilter.h:250 [inline] >>   ipv6_rcv+0xf1f/0x1f80 net/ipv6/ip6_input.c:208 >>   __netif_receive_skb_core+0x1a3e/0x3450 net/core/dev.c:4461 >>   __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4526 >>   process_backlog+0x203/0x740 net/core/dev.c:5205 >>   napi_poll net/core/dev.c:5603 [inline] >>   net_rx_action+0x792/0x1910 net/core/dev.c:5669 >>   __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 >>   do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1115 >>    >>   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+0xba6/0x2390 net/ipv6/ip6_output.c:121 >>   ip6_finish_output+0x2f9/0x920 net/ipv6/ip6_output.c:146 >>   NF_HOOK_COND include/linux/netfilter.h:239 [inline] >>   ip6_output+0x1eb/0x840 net/ipv6/ip6_output.c:163 >>   dst_output include/net/dst.h:460 [inline] >>   NF_HOOK include/linux/netfilter.h:250 [inline] >>   ip6_xmit+0xd75/0x2080 net/ipv6/ip6_output.c:269 >>   inet6_csk_xmit+0x2fc/0x580 net/ipv6/inet6_connection_sock.c:139 >>   tcp_transmit_skb+0x1b12/0x38b0 net/ipv4/tcp_output.c:1176 >>   tcp_write_xmit+0x680/0x5190 net/ipv4/tcp_output.c:2367 >>   __tcp_push_pending_frames+0xa0/0x250 net/ipv4/tcp_output.c:2543 >>   tcp_send_fin+0x1b0/0xd20 net/ipv4/tcp_output.c:3087 >>   tcp_close+0xbe0/0xfc0 net/ipv4/tcp.c:2234 >>   inet_release+0xed/0x1c0 net/ipv4/af_inet.c:426 >>   inet6_release+0x50/0x70 net/ipv6/af_inet6.c:432 >>   sock_release+0x8d/0x1e0 net/socket.c:600 >>   sock_close+0x16/0x20 net/socket.c:1129 >>   __fput+0x327/0x7e0 fs/file_table.c:210 >>   ____fput+0x15/0x20 fs/file_table.c:244 >>   task_work_run+0x199/0x270 kernel/task_work.c:113 >>   exit_task_work include/linux/task_work.h:22 [inline] >>   do_exit+0x9bb/0x1ad0 kernel/exit.c:865 >>   do_group_exit+0x149/0x400 kernel/exit.c:968 >>   get_signal+0x73f/0x16c0 kernel/signal.c:2335 >>   do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:809 >>   exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 >>   prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] >>   syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 >>   entry_SYSCALL_64_fastpath+0x94/0x96 >>  RIP: 0033:0x4456e9 >>  RSP: 002b:00007fb4de631da8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca >>  RAX: fffffffffffffe00 RBX: 00000000006dac3c RCX: 00000000004456e9 >>  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000006dac3c >>  RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 >>  R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac38 >>  R13: 0100000000000000 R14: 00007fb4de6329c0 R15: 0000000000000009 >> >>  Allocated by task 3196: >>   save_stack+0x43/0xd0 mm/kasan/kasan.c:447 >>   set_track mm/kasan/kasan.c:459 [inline] >>   kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 >>   kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 >>   kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544 >>   sk_prot_alloc+0x65/0x2a0 net/core/sock.c:1463 >>   sk_clone_lock+0x152/0x1570 net/core/sock.c:1649 >>   inet_csk_clone_lock+0x92/0x4f0 net/ipv4/inet_connection_sock.c:781 >>   tcp_create_openreq_child+0x9b/0x1b70 net/ipv4/tcp_minisocks.c:449 >>   tcp_v6_syn_recv_sock+0x22d/0x23a0 net/ipv6/tcp_ipv6.c:1123 >>   tcp_get_cookie_sock+0x102/0x540 net/ipv4/syncookies.c:213 >>   cookie_v6_check+0x177d/0x2160 net/ipv6/syncookies.c:255 >>   tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1008 [inline] >>   tcp_v6_do_rcv+0xe4d/0x11c0 net/ipv6/tcp_ipv6.c:1316 >>   tcp_v6_rcv+0x22ee/0x2b40 net/ipv6/tcp_ipv6.c:1510 >>   ip6_input_finish+0x36f/0x1700 net/ipv6/ip6_input.c:284 >>   NF_HOOK include/linux/netfilter.h:250 [inline] >>   ip6_input+0xe9/0x560 net/ipv6/ip6_input.c:327 >>   dst_input include/net/dst.h:466 [inline] >>   ip6_rcv_finish+0x1a9/0x7a0 net/ipv6/ip6_input.c:71 >>   NF_HOOK include/linux/netfilter.h:250 [inline] >>   ipv6_rcv+0xf1f/0x1f80 net/ipv6/ip6_input.c:208 >>   __netif_receive_skb_core+0x1a3e/0x3450 net/core/dev.c:4461 >>   __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4526 >>   process_backlog+0x203/0x740 net/core/dev.c:5205 >>   napi_poll net/core/dev.c:5603 [inline] >>   net_rx_action+0x792/0x1910 net/core/dev.c:5669 >>   __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 >> >>  Freed by task 0: >>  (stack is not available) >> >>  The buggy address belongs to the object at ffff8801cbdd6a80 >>   which belongs to the cache TCP of size 2528 >>  The buggy address is located 0 bytes to the right of >>   2528-byte region [ffff8801cbdd6a80, ffff8801cbdd7460) >>  The buggy address belongs to the page: >>  page:000000006145927c count:1 mapcount:0 mapping:00000000d41dd7c1 >>  index:0xffff8801cbdd7ffd compound_mapcount: 0 >>  flags: 0x2fffc0000008100(slab|head) >>  raw: 02fffc0000008100 ffff8801cbdd6000 ffff8801cbdd7ffd 0000000100000003 >>  raw: ffffea00074ef120 ffff8801d82b7248 ffff8801d798b640 0000000000000000 >>  page dumped because: kasan: bad access detected >> >>  Memory state around the buggy address: >>   ffff8801cbdd7300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >>   ffff8801cbdd7380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >>>  ffff8801cbdd7400: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc >> >>                                                         ^ >>   ffff8801cbdd7480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>   ffff8801cbdd7500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >>  ================================================================== >> >>  --- >>  This bug is generated by a dumb bot. It may contain errors. >>  See https://goo.gl/tpsmEJ for details. >>  Direct all questions to syzkaller@googlegroups.com. >> >>  syzbot will keep track of this bug report. >>  If you forgot to add the Reported-by tag, once the fix for this bug is >>  merged >>  into any tree, please reply to this email with: >>  #syz fix: exact-commit-title >>  If you want to test a patch for this bug, please reply with: >>  #syz test: git://repo/address.git branch >>  and provide the patch inline or as an attachment. >>  To mark this as a duplicate of another syzbot report, please reply with: >>  #syz dup: exact-subject-of-another-report >>  If it's a one-off invalid bug report, please reply with: >>  #syz invalid >>  Note: if the crash happens again, it will cause creation of a new bug >>  report. >>  Note: all commands must start from beginning of the line in the email body.