Re: BUG: corrupted list in sctp_association_free

[Dmitry Vyukov]

On Tue, Mar 13, 2018 at 1:44 PM, Xin Long <lucien.xin@xxxxxxxxx> wrote:
> On Tue, Mar 13, 2018 at 3:34 PM, syzbot
> <syzbot+e56a5d45f832ef33ad2f@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>> Hello,
>>
>> syzbot hit the following crash on net-next commit
>> fd372a7a9e5e9d8011a0222d10edd3523abcd3b1 (Thu Mar 8 19:43:48 2018 +0000)
>> Merge tag 'mlx5-updates-2018-02-28-2' of
>> git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux
>>
>> Unfortunately, I don't have any reproducer for this crash yet.
>> Raw console output is attached.
>> compiler: gcc (GCC) 7.1.1 20170620
>> .config is attached.
>>
>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>> Reported-by: syzbot+e56a5d45f832ef33ad2f@xxxxxxxxxxxxxxxxxxxxxxxxx
>> 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.
>>
>> selinux_nlmsg_perm: 1 callbacks suppressed
>> SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
>> sclass=netlink_route_socket pig=12502 comm=syz-executor3
>> SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
>> sclass=netlink_route_socket pig=12528 comm=syz-executor3
>> list_del corruption, 00000000fcc5fb27->next is LIST_POISON1
>> (00000000cb16e51d)
>> ------------[ cut here ]------------
>> kernel BUG at lib/list_debug.c:47!
>> invalid opcode: 0000 [#1] SMP KASAN
>> Dumping ftrace buffer:
>>    (ftrace buffer empty)
>> Modules linked in:
>> CPU: 0 PID: 12537 Comm: syz-executor2 Not tainted 4.16.0-rc4+ #258
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
>> Google 01/01/2011
>> RIP: 0010:__list_del_entry_valid+0xd3/0x150 lib/list_debug.c:45
>> RSP: 0018:ffff8801b6387778 EFLAGS: 00010286
>> RAX: 000000000000004e RBX: dead000000000200 RCX: 0000000000000000
>> RDX: 000000000000004e RSI: ffffc90002ed6000 RDI: ffffed0036c70ee3
>> RBP: ffff8801b6387790 R08: 1ffff10036c70e3b R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000000 R12: dead000000000100
>> R13: ffff8801d3164000 R14: ffff8801d8502220 R15: ffff8801b6387c58
>> FS:  00007ff42042f700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
>> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 00007ff42040ddb8 CR3: 00000001bd840003 CR4: 00000000001606f0
>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> Call Trace:
>>  __list_del_entry include/linux/list.h:117 [inline]
>>  list_del include/linux/list.h:125 [inline]
>>  sctp_association_free+0x133/0x930 net/sctp/associola.c:341
>>  sctp_sendmsg+0xc67/0x1a80 net/sctp/socket.c:2075
>>  inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763
>>  sock_sendmsg_nosec net/socket.c:629 [inline]
>>  sock_sendmsg+0xca/0x110 net/socket.c:639
>>  SYSC_sendto+0x361/0x5c0 net/socket.c:1748
>>  SyS_sendto+0x40/0x50 net/socket.c:1716
>>  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
>>  entry_SYSCALL_64_after_hwframe+0x42/0xb7
>> RIP: 0033:0x453e69
>> RSP: 002b:00007ff42042ec68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
>> RAX: ffffffffffffffda RBX: 00007ff42042f6d4 RCX: 0000000000453e69
>> RDX: 0000000000000001 RSI: 0000000020000340 RDI: 0000000000000015
>> RBP: 000000000072c0c8 R08: 00000000204d9000 R09: 000000000000001c
>> R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
>> R13: 00000000000004cd R14: 00000000006f73d8 R15: 0000000000000003
>> Code: 8f 00 00 00 49 8b 54 24 08 48 39 f2 75 3b 48 83 c4 08 b8 01 00 00 00
>> 5b 41 5c 5d c3 4c 89 e2 48 c7 c7 c0 7c 40 86 e8 75 f6 fb fe <0f> 0b 48 c7 c7
>> 20 7d 40 86 e8 67 f6 fb fe 0f 0b 48 c7 c7 80 7d
>> RIP: __list_del_entry_valid+0xd3/0x150 lib/list_debug.c:45 RSP:
>> ffff8801b6387778
>> ---[ end trace a6b157f61f9bd43a ]---
>> Kernel panic - not syncing: Fatal exception
>> Dumping ftrace buffer:
>>    (ftrace buffer empty)
>> Kernel Offset: disabled
>> Rebooting in 86400 seconds..
>>
>>
>> ---
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> I'd think the patch Neil just posted would fix it.


Hi Xin,

Could you point me to that commit? We need to tell syzbot about it.

Thanks