* net: GPF in rt6_get_cookie
@ 2016-11-26 16:23 Dmitry Vyukov
2016-11-30 10:39 ` Andrey Konovalov
0 siblings, 1 reply; 4+ messages in thread
From: Dmitry Vyukov @ 2016-11-26 16:23 UTC (permalink / raw)
To: David Miller, Alexey Kuznetsov, James Morris, Hideaki YOSHIFUJI,
Patrick McHardy, netdev, LKML, Eric Dumazet
Cc: syzkaller
Hello,
I got several GPFs in rt6_get_cookie while running syzkaller:
general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 2 PID: 10156 Comm: syz-executor Not tainted 4.9.0-rc5+ #54
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff880016f40480 task.stack: ffff88000fc00000
RIP: 0010:[<ffffffff87a209e8>] [< inline >] rt6_get_cookie
include/net/ip6_fib.h:174
RIP: 0010:[<ffffffff87a209e8>] [<ffffffff87a209e8>]
sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
RSP: 0018:ffff88000fc07298 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc900029f5000
RDX: 0000000000000015 RSI: 0000000000000001 RDI: 00000000000000a8
RBP: ffff88000fc07580 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffff880066cd0068
R13: 1ffff10001f80e92 R14: ffff880066cd0040 R15: ffff88005f2d2808
FS: 00007f52c41f7700(0000) GS:ffff88006d000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020016000 CR3: 0000000065dd7000 CR4: 00000000000006e0
DR0: 0000000000000400 DR1: 0000000000000400 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Stack:
ffffffff87a210f6 ffffffff8701ad45 ffff88006768ec20 ffff88006768ec20
0000000000000000 0000000016f40480 ffff88000fc07450 1ffff1000cd9a017
ffff88006768ec00 ffff880066fc0730 ffff880066cd0068 1ffff10001f80e66
Call Trace:
[<ffffffff879a313d>] sctp_transport_route+0xad/0x430 net/sctp/transport.c:279
[<ffffffff8799b106>] sctp_assoc_add_peer+0x5a6/0x13e0 net/sctp/associola.c:641
[<ffffffff879e8911>] sctp_sendmsg+0x1921/0x3bc0 net/sctp/socket.c:1864
[<ffffffff8701ad45>] inet_sendmsg+0x385/0x590 net/ipv4/af_inet.c:734
[< inline >] sock_sendmsg_nosec net/socket.c:621
[<ffffffff86a6d54f>] sock_sendmsg+0xcf/0x110 net/socket.c:631
[<ffffffff86a6ede0>] SYSC_sendto+0x660/0x810 net/socket.c:1656
[<ffffffff86a71dd5>] SyS_sendto+0x45/0x60 net/socket.c:1624
[<ffffffff88149dc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
Code: 00 00 48 8b 84 24 88 00 00 00 48 8b 58 40 e8 80 76 cc f9 48 8d
bb a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80>
3c 02 00 0f 85 56 0f 00 00 48 8b 9b a8 00 00 00 45 31 ed 48
RIP [< inline >] rt6_get_cookie include/net/ip6_fib.h:174
RIP [<ffffffff87a209e8>] sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
RSP <ffff88000fc07298>
---[ end trace b8d1354fa571700d ]---
general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 3 PID: 22744 Comm: syz-executor Not tainted 4.9.0-rc5+ #54
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff88006b92a840 task.stack: ffff88006a730000
RIP: 0010:[<ffffffff87a209e8>] [< inline >] rt6_get_cookie
include/net/ip6_fib.h:174
RIP: 0010:[<ffffffff87a209e8>] [<ffffffff87a209e8>]
sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
RSP: 0018:ffff88006a736b88 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90003c4f000
RDX: 0000000000000015 RSI: 0000000000000001 RDI: 00000000000000a8
RBP: ffff88006a736e68 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffff880064cff268
R13: 1ffff1000d4e6db0 R14: ffff880064cff240 R15: ffff88006a4b6808
FS: 00007f74f4ec9700(0000) GS:ffff88006d100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002070effc CR3: 000000003bd2f000 CR4: 00000000000006e0
DR0: 0000000000000400 DR1: 0000000000000400 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Stack:
ffffffff87a210f6 ffffffff000bbd2d ffff88006c2cd5a0 ffff88006c2cd5a0
0000000000000000 000000006ccb46c0 ffff88006a736d40 1ffff1000c99fe57
ffff88006c2cd500 ffff8800658b1f30 ffff880064cff268 1ffff1000d4e6d84
Call Trace:
[<ffffffff879a313d>] sctp_transport_route+0xad/0x430 net/sctp/transport.c:279
[<ffffffff8799b106>] sctp_assoc_add_peer+0x5a6/0x13e0 net/sctp/associola.c:641
[<ffffffff879e4358>] __sctp_connect+0x288/0xc90 net/sctp/socket.c:1178
[<ffffffff879e4f0b>] __sctp_setsockopt_connectx+0x1ab/0x200
net/sctp/socket.c:1332
[< inline >] sctp_getsockopt_connectx3 net/sctp/socket.c:1417
[<ffffffff879fd2bd>] sctp_getsockopt+0x36ed/0x6800 net/sctp/socket.c:6474
[<ffffffff86a76c0a>] sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:2649
[< inline >] SYSC_getsockopt net/socket.c:1788
[<ffffffff86a724d7>] SyS_getsockopt+0x257/0x390 net/socket.c:1770
[<ffffffff88149dc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
Code: 00 00 48 8b 84 24 88 00 00 00 48 8b 58 40 e8 80 76 cc f9 48 8d
bb a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80>
3c 02 00 0f 85 56 0f 00 00 48 8b 9b a8 00 00 00 45 31 ed 48
RIP [< inline >] rt6_get_cookie include/net/ip6_fib.h:174
RIP [<ffffffff87a209e8>] sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
RSP <ffff88006a736b88>
---[ end trace f42d1c14cb6d2835 ]---
This happened on commit a25f0944ba9b1d8a6813fd6f1a86f1bd59ac25a6 (Nov 13).
Unfortunately this is not reproducible.
The line is:
return rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
Can it be a data race? rt->rt6i_node != NULL, but the next moment it
is already NULL? That would explain the crash and non-reproducibility
(need ThreadSanitizer!).
This always happened when called from sctp code, but I don't know if
it is relevant or not. It happened only 3 times.
Thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: net: GPF in rt6_get_cookie
2016-11-26 16:23 net: GPF in rt6_get_cookie Dmitry Vyukov
@ 2016-11-30 10:39 ` Andrey Konovalov
2016-11-30 11:00 ` Hannes Frederic Sowa
0 siblings, 1 reply; 4+ messages in thread
From: Andrey Konovalov @ 2016-11-30 10:39 UTC (permalink / raw)
To: syzkaller
Cc: David Miller, Alexey Kuznetsov, James Morris, Hideaki YOSHIFUJI,
Patrick McHardy, netdev, LKML, Eric Dumazet
On Sat, Nov 26, 2016 at 5:23 PM, 'Dmitry Vyukov' via syzkaller
<syzkaller@googlegroups.com> wrote:
> Hello,
>
> I got several GPFs in rt6_get_cookie while running syzkaller:
>
> general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
> Dumping ftrace buffer:
> (ftrace buffer empty)
> Modules linked in:
> CPU: 2 PID: 10156 Comm: syz-executor Not tainted 4.9.0-rc5+ #54
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> task: ffff880016f40480 task.stack: ffff88000fc00000
> RIP: 0010:[<ffffffff87a209e8>] [< inline >] rt6_get_cookie
> include/net/ip6_fib.h:174
> RIP: 0010:[<ffffffff87a209e8>] [<ffffffff87a209e8>]
> sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
> RSP: 0018:ffff88000fc07298 EFLAGS: 00010202
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc900029f5000
> RDX: 0000000000000015 RSI: 0000000000000001 RDI: 00000000000000a8
> RBP: ffff88000fc07580 R08: 0000000000000000 R09: 0000000000000001
> R10: 0000000000000000 R11: 0000000000000000 R12: ffff880066cd0068
> R13: 1ffff10001f80e92 R14: ffff880066cd0040 R15: ffff88005f2d2808
> FS: 00007f52c41f7700(0000) GS:ffff88006d000000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000020016000 CR3: 0000000065dd7000 CR4: 00000000000006e0
> DR0: 0000000000000400 DR1: 0000000000000400 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
> Stack:
> ffffffff87a210f6 ffffffff8701ad45 ffff88006768ec20 ffff88006768ec20
> 0000000000000000 0000000016f40480 ffff88000fc07450 1ffff1000cd9a017
> ffff88006768ec00 ffff880066fc0730 ffff880066cd0068 1ffff10001f80e66
> Call Trace:
> [<ffffffff879a313d>] sctp_transport_route+0xad/0x430 net/sctp/transport.c:279
> [<ffffffff8799b106>] sctp_assoc_add_peer+0x5a6/0x13e0 net/sctp/associola.c:641
> [<ffffffff879e8911>] sctp_sendmsg+0x1921/0x3bc0 net/sctp/socket.c:1864
> [<ffffffff8701ad45>] inet_sendmsg+0x385/0x590 net/ipv4/af_inet.c:734
> [< inline >] sock_sendmsg_nosec net/socket.c:621
> [<ffffffff86a6d54f>] sock_sendmsg+0xcf/0x110 net/socket.c:631
> [<ffffffff86a6ede0>] SYSC_sendto+0x660/0x810 net/socket.c:1656
> [<ffffffff86a71dd5>] SyS_sendto+0x45/0x60 net/socket.c:1624
> [<ffffffff88149dc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
> Code: 00 00 48 8b 84 24 88 00 00 00 48 8b 58 40 e8 80 76 cc f9 48 8d
> bb a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80>
> 3c 02 00 0f 85 56 0f 00 00 48 8b 9b a8 00 00 00 45 31 ed 48
> RIP [< inline >] rt6_get_cookie include/net/ip6_fib.h:174
> RIP [<ffffffff87a209e8>] sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
> RSP <ffff88000fc07298>
> ---[ end trace b8d1354fa571700d ]---
>
>
> general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
> Dumping ftrace buffer:
> (ftrace buffer empty)
> Modules linked in:
> CPU: 3 PID: 22744 Comm: syz-executor Not tainted 4.9.0-rc5+ #54
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> task: ffff88006b92a840 task.stack: ffff88006a730000
> RIP: 0010:[<ffffffff87a209e8>] [< inline >] rt6_get_cookie
> include/net/ip6_fib.h:174
> RIP: 0010:[<ffffffff87a209e8>] [<ffffffff87a209e8>]
> sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
> RSP: 0018:ffff88006a736b88 EFLAGS: 00010202
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90003c4f000
> RDX: 0000000000000015 RSI: 0000000000000001 RDI: 00000000000000a8
> RBP: ffff88006a736e68 R08: 0000000000000000 R09: 0000000000000001
> R10: 0000000000000000 R11: 0000000000000000 R12: ffff880064cff268
> R13: 1ffff1000d4e6db0 R14: ffff880064cff240 R15: ffff88006a4b6808
> FS: 00007f74f4ec9700(0000) GS:ffff88006d100000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000002070effc CR3: 000000003bd2f000 CR4: 00000000000006e0
> DR0: 0000000000000400 DR1: 0000000000000400 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
> Stack:
> ffffffff87a210f6 ffffffff000bbd2d ffff88006c2cd5a0 ffff88006c2cd5a0
> 0000000000000000 000000006ccb46c0 ffff88006a736d40 1ffff1000c99fe57
> ffff88006c2cd500 ffff8800658b1f30 ffff880064cff268 1ffff1000d4e6d84
> Call Trace:
> [<ffffffff879a313d>] sctp_transport_route+0xad/0x430 net/sctp/transport.c:279
> [<ffffffff8799b106>] sctp_assoc_add_peer+0x5a6/0x13e0 net/sctp/associola.c:641
> [<ffffffff879e4358>] __sctp_connect+0x288/0xc90 net/sctp/socket.c:1178
> [<ffffffff879e4f0b>] __sctp_setsockopt_connectx+0x1ab/0x200
> net/sctp/socket.c:1332
> [< inline >] sctp_getsockopt_connectx3 net/sctp/socket.c:1417
> [<ffffffff879fd2bd>] sctp_getsockopt+0x36ed/0x6800 net/sctp/socket.c:6474
> [<ffffffff86a76c0a>] sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:2649
> [< inline >] SYSC_getsockopt net/socket.c:1788
> [<ffffffff86a724d7>] SyS_getsockopt+0x257/0x390 net/socket.c:1770
> [<ffffffff88149dc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
> Code: 00 00 48 8b 84 24 88 00 00 00 48 8b 58 40 e8 80 76 cc f9 48 8d
> bb a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80>
> 3c 02 00 0f 85 56 0f 00 00 48 8b 9b a8 00 00 00 45 31 ed 48
> RIP [< inline >] rt6_get_cookie include/net/ip6_fib.h:174
> RIP [<ffffffff87a209e8>] sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
> RSP <ffff88006a736b88>
> ---[ end trace f42d1c14cb6d2835 ]---
>
> This happened on commit a25f0944ba9b1d8a6813fd6f1a86f1bd59ac25a6 (Nov 13).
>
> Unfortunately this is not reproducible.
>
> The line is:
>
> return rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
>
> Can it be a data race? rt->rt6i_node != NULL, but the next moment it
> is already NULL? That would explain the crash and non-reproducibility
> (need ThreadSanitizer!).
>
> This always happened when called from sctp code, but I don't know if
> it is relevant or not. It happened only 3 times.
I'm seeing similar crashes from ipv6 and dccp code, reports below.
===
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 30320 Comm: syz-executor0 Not tainted 4.9.0-rc6+ #462
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff880069c10040 task.stack: ffff880069f20000
RIP: 0010:[<ffffffff839eec82>] [< inline >] rt6_get_cookie
include/net/ip6_fib.h:174
RIP: 0010:[<ffffffff839eec82>] [< inline >] ip6_dst_store
include/net/ip6_route.h:174
RIP: 0010:[<ffffffff839eec82>] [<ffffffff839eec82>]
dccp_v6_connect+0x762/0x14e0 net/dccp/ipv6.c:899
RSP: 0018:ffff880069f27ab0 EFLAGS: 00010202
RAX: ffff880069c10040 RBX: ffff88003b5b0040 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffc90000e6c000 RDI: 00000000000000a8
RBP: ffff880069f27c08 R08: 0000000000000015 R09: ffffffff839eec65
R10: 1ffff1000d2d78e0 R11: dffffc0000000000 R12: ffff880069f27e00
R13: ffff8800696bc6c0 R14: ffff88003b5b08e8 R15: ffff88003b5b08e8
FS: 00007f04712ef700(0000) GS:ffff88003ed00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004ad010 CR3: 0000000037c6a000 CR4: 00000000000006e0
Stack:
ffff880069f27c58 ffff88003b5b04a0 ffff88003b5b0088 ffff88003b5b0078
ffff880069f27e02 ffff88003b5b0052 00000000ffffffff 0000000000000000
1ffff1000d3e4f60 0000000000000000 0000000041b58ab3 ffffffff84a3599d
Call Trace:
[<ffffffff8329b087>] __inet_stream_connect+0x2a7/0xb30 net/ipv4/af_inet.c:594
[<ffffffff8329b965>] inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:655
[<ffffffff82c9e5f4>] SYSC_connect+0x244/0x2f0 net/socket.c:1548
[<ffffffff82ca0de4>] SyS_connect+0x24/0x30 net/socket.c:1529
[<ffffffff81006485>] do_syscall_64+0x195/0x490 arch/x86/entry/common.c:280
[<ffffffff840f2d09>] entry_SYSCALL64_slow_path+0x25/0x25
Code: 49 8b 7d 40 48 89 7c 24 38 e8 cb 50 a6 fd 48 8b 4c 24 38 48 ba
00 00 00 00 00 fc ff df 48 8d b9 a8 00 00 00 49 89 f8 49 c1 e8 03 <41>
80 3c 10 00 0f 85 52 0d 00 00 48 8b 81 a8 00 00 00 48 85 c0
RIP [< inline >] rt6_get_cookie include/net/ip6_fib.h:174
RIP [< inline >] ip6_dst_store include/net/ip6_route.h:174
RIP [<ffffffff839eec82>] dccp_v6_connect+0x762/0x14e0 net/dccp/ipv6.c:899
RSP <ffff880069f27ab0>
---[ end trace e7d9d916f3bf26c5 ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: disabled
===
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 3 PID: 21865 Comm: syz-executor0 Not tainted 4.9.0-rc6+ #462
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff88003bacc480 task.stack: ffff88003a038000
RIP: 0010:[<ffffffff834c9c7f>] [< inline >] rt6_get_cookie
include/net/ip6_fib.h:174
RIP: 0010:[<ffffffff834c9c7f>] [< inline >] ip6_dst_store
include/net/ip6_route.h:174
RIP: 0010:[<ffffffff834c9c7f>] [<ffffffff834c9c7f>]
ip6_datagram_dst_update+0x75f/0xe70 net/ipv6/datagram.c:108
RSP: 0018:ffff88003a03fb48 EFLAGS: 00010202
RAX: ffff88003bacc480 RBX: ffff880068e887c0 RCX: 0000000000000001
RDX: 0000000000000015 RSI: ffffc90000de4000 RDI: 00000000000000a8
RBP: ffff88003a03fc88 R08: 0000000000004000 R09: ffffffff834c9c67
R10: dffffc0000000000 R11: dffffc0000000000 R12: ffff880068e88cf0
R13: ffff88006ba75a40 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f1d4c9f3700(0000) GS:ffff88006e100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004ad010 CR3: 000000006cde5000 CR4: 00000000000006e0
Stack:
ffffffff834c997b 0000000041b58ab3 ffffffff849dee58 1ffff10007407f70
ffff880068e887f8 ffff880068e887f8 ffff880068e88cf0 0000000041b58ab3
ffffffff84a35071 ffffffff834c9520 0000000000000007 ffff88003bacc480
Call Trace:
[< inline >] __ip6_datagram_connect net/ipv6/datagram.c:246
[<ffffffff834cab95>] ip6_datagram_connect+0x375/0xcc0 net/ipv6/datagram.c:261
[<ffffffff834cb53f>] ip6_datagram_connect_v6_only+0x5f/0x80
net/ipv6/datagram.c:273
[<ffffffff8329a3ab>] inet_dgram_connect+0x11b/0x200 net/ipv4/af_inet.c:530
[<ffffffff82c9e5f4>] SYSC_connect+0x244/0x2f0 net/socket.c:1548
[<ffffffff82ca0de4>] SyS_connect+0x24/0x30 net/socket.c:1529
[<ffffffff840f2c41>] entry_SYSCALL_64_fastpath+0x1f/0xc2
Code: 80 3c 08 00 0f 85 96 05 00 00 4d 8b 7d 40 e8 c9 a0 f8 fd 49 8d
bf a8 00 00 00 49 ba 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <42>
80 3c 12 00 0f 85 74 05 00 00 4d 8b bf a8 00 00 00 4d 85 ff
RIP [< inline >] rt6_get_cookie include/net/ip6_fib.h:174
RIP [< inline >] ip6_dst_store include/net/ip6_route.h:174
RIP [<ffffffff834c9c7f>] ip6_datagram_dst_update+0x75f/0xe70
net/ipv6/datagram.c:108
RSP <ffff88003a03fb48>
---[ end trace 148fc8ac80034c6f ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: disabled
===
>
> Thanks.
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller+unsubscribe@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: net: GPF in rt6_get_cookie
2016-11-30 10:39 ` Andrey Konovalov
@ 2016-11-30 11:00 ` Hannes Frederic Sowa
2016-11-30 11:10 ` Andrey Konovalov
0 siblings, 1 reply; 4+ messages in thread
From: Hannes Frederic Sowa @ 2016-11-30 11:00 UTC (permalink / raw)
To: Andrey Konovalov, syzkaller
Cc: David Miller, Alexey Kuznetsov, James Morris, Hideaki YOSHIFUJI,
Patrick McHardy, netdev, LKML, Eric Dumazet
Hi
On 30.11.2016 11:39, Andrey Konovalov wrote:
> On Sat, Nov 26, 2016 at 5:23 PM, 'Dmitry Vyukov' via syzkaller
> <syzkaller@googlegroups.com> wrote:
>> Hello,
>>
>> I got several GPFs in rt6_get_cookie while running syzkaller:
>>
>> general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
>> Dumping ftrace buffer:
>> (ftrace buffer empty)
>> Modules linked in:
>> CPU: 2 PID: 10156 Comm: syz-executor Not tainted 4.9.0-rc5+ #54
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> task: ffff880016f40480 task.stack: ffff88000fc00000
>> RIP: 0010:[<ffffffff87a209e8>] [< inline >] rt6_get_cookie
>> include/net/ip6_fib.h:174
>> RIP: 0010:[<ffffffff87a209e8>] [<ffffffff87a209e8>]
>> sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
>> RSP: 0018:ffff88000fc07298 EFLAGS: 00010202
>> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc900029f5000
>> RDX: 0000000000000015 RSI: 0000000000000001 RDI: 00000000000000a8
>> RBP: ffff88000fc07580 R08: 0000000000000000 R09: 0000000000000001
>> R10: 0000000000000000 R11: 0000000000000000 R12: ffff880066cd0068
>> R13: 1ffff10001f80e92 R14: ffff880066cd0040 R15: ffff88005f2d2808
>> FS: 00007f52c41f7700(0000) GS:ffff88006d000000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 0000000020016000 CR3: 0000000065dd7000 CR4: 00000000000006e0
>> DR0: 0000000000000400 DR1: 0000000000000400 DR2: 0000000000000000
>> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
>> Stack:
>> ffffffff87a210f6 ffffffff8701ad45 ffff88006768ec20 ffff88006768ec20
>> 0000000000000000 0000000016f40480 ffff88000fc07450 1ffff1000cd9a017
>> ffff88006768ec00 ffff880066fc0730 ffff880066cd0068 1ffff10001f80e66
>> Call Trace:
>> [<ffffffff879a313d>] sctp_transport_route+0xad/0x430 net/sctp/transport.c:279
>> [<ffffffff8799b106>] sctp_assoc_add_peer+0x5a6/0x13e0 net/sctp/associola.c:641
>> [<ffffffff879e8911>] sctp_sendmsg+0x1921/0x3bc0 net/sctp/socket.c:1864
>> [<ffffffff8701ad45>] inet_sendmsg+0x385/0x590 net/ipv4/af_inet.c:734
>> [< inline >] sock_sendmsg_nosec net/socket.c:621
>> [<ffffffff86a6d54f>] sock_sendmsg+0xcf/0x110 net/socket.c:631
>> [<ffffffff86a6ede0>] SYSC_sendto+0x660/0x810 net/socket.c:1656
>> [<ffffffff86a71dd5>] SyS_sendto+0x45/0x60 net/socket.c:1624
>> [<ffffffff88149dc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
>> Code: 00 00 48 8b 84 24 88 00 00 00 48 8b 58 40 e8 80 76 cc f9 48 8d
>> bb a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80>
>> 3c 02 00 0f 85 56 0f 00 00 48 8b 9b a8 00 00 00 45 31 ed 48
>> RIP [< inline >] rt6_get_cookie include/net/ip6_fib.h:174
>> RIP [<ffffffff87a209e8>] sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
>> RSP <ffff88000fc07298>
>> ---[ end trace b8d1354fa571700d ]---
>>
>>
>> general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
>> Dumping ftrace buffer:
>> (ftrace buffer empty)
>> Modules linked in:
>> CPU: 3 PID: 22744 Comm: syz-executor Not tainted 4.9.0-rc5+ #54
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> task: ffff88006b92a840 task.stack: ffff88006a730000
>> RIP: 0010:[<ffffffff87a209e8>] [< inline >] rt6_get_cookie
>> include/net/ip6_fib.h:174
>> RIP: 0010:[<ffffffff87a209e8>] [<ffffffff87a209e8>]
>> sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
>> RSP: 0018:ffff88006a736b88 EFLAGS: 00010202
>> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90003c4f000
>> RDX: 0000000000000015 RSI: 0000000000000001 RDI: 00000000000000a8
>> RBP: ffff88006a736e68 R08: 0000000000000000 R09: 0000000000000001
>> R10: 0000000000000000 R11: 0000000000000000 R12: ffff880064cff268
>> R13: 1ffff1000d4e6db0 R14: ffff880064cff240 R15: ffff88006a4b6808
>> FS: 00007f74f4ec9700(0000) GS:ffff88006d100000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 000000002070effc CR3: 000000003bd2f000 CR4: 00000000000006e0
>> DR0: 0000000000000400 DR1: 0000000000000400 DR2: 0000000000000000
>> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
>> Stack:
>> ffffffff87a210f6 ffffffff000bbd2d ffff88006c2cd5a0 ffff88006c2cd5a0
>> 0000000000000000 000000006ccb46c0 ffff88006a736d40 1ffff1000c99fe57
>> ffff88006c2cd500 ffff8800658b1f30 ffff880064cff268 1ffff1000d4e6d84
>> Call Trace:
>> [<ffffffff879a313d>] sctp_transport_route+0xad/0x430 net/sctp/transport.c:279
>> [<ffffffff8799b106>] sctp_assoc_add_peer+0x5a6/0x13e0 net/sctp/associola.c:641
>> [<ffffffff879e4358>] __sctp_connect+0x288/0xc90 net/sctp/socket.c:1178
>> [<ffffffff879e4f0b>] __sctp_setsockopt_connectx+0x1ab/0x200
>> net/sctp/socket.c:1332
>> [< inline >] sctp_getsockopt_connectx3 net/sctp/socket.c:1417
>> [<ffffffff879fd2bd>] sctp_getsockopt+0x36ed/0x6800 net/sctp/socket.c:6474
>> [<ffffffff86a76c0a>] sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:2649
>> [< inline >] SYSC_getsockopt net/socket.c:1788
>> [<ffffffff86a724d7>] SyS_getsockopt+0x257/0x390 net/socket.c:1770
>> [<ffffffff88149dc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
>> Code: 00 00 48 8b 84 24 88 00 00 00 48 8b 58 40 e8 80 76 cc f9 48 8d
>> bb a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80>
>> 3c 02 00 0f 85 56 0f 00 00 48 8b 9b a8 00 00 00 45 31 ed 48
>> RIP [< inline >] rt6_get_cookie include/net/ip6_fib.h:174
>> RIP [<ffffffff87a209e8>] sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
>> RSP <ffff88006a736b88>
>> ---[ end trace f42d1c14cb6d2835 ]---
>>
>> This happened on commit a25f0944ba9b1d8a6813fd6f1a86f1bd59ac25a6 (Nov 13).
>>
>> Unfortunately this is not reproducible.
>>
>> The line is:
>>
>> return rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
>>
>> Can it be a data race? rt->rt6i_node != NULL, but the next moment it
>> is already NULL? That would explain the crash and non-reproducibility
>> (need ThreadSanitizer!).
>>
>> This always happened when called from sctp code, but I don't know if
>> it is relevant or not. It happened only 3 times.
>
> I'm seeing similar crashes from ipv6 and dccp code, reports below.
>
> [...]
Thanks for the report.
Do you have a thread running that concurrently mutates the routing table?
Bye,
Hannes
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: net: GPF in rt6_get_cookie
2016-11-30 11:00 ` Hannes Frederic Sowa
@ 2016-11-30 11:10 ` Andrey Konovalov
0 siblings, 0 replies; 4+ messages in thread
From: Andrey Konovalov @ 2016-11-30 11:10 UTC (permalink / raw)
To: Hannes Frederic Sowa
Cc: syzkaller, David Miller, Alexey Kuznetsov, James Morris,
Hideaki YOSHIFUJI, Patrick McHardy, netdev, LKML, Eric Dumazet
On Wed, Nov 30, 2016 at 12:00 PM, Hannes Frederic Sowa
<hannes@stressinduktion.org> wrote:
> Hi
>
> On 30.11.2016 11:39, Andrey Konovalov wrote:
>> On Sat, Nov 26, 2016 at 5:23 PM, 'Dmitry Vyukov' via syzkaller
>> <syzkaller@googlegroups.com> wrote:
>>> Hello,
>>>
>>> I got several GPFs in rt6_get_cookie while running syzkaller:
>>>
>>> general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
>>> Dumping ftrace buffer:
>>> (ftrace buffer empty)
>>> Modules linked in:
>>> CPU: 2 PID: 10156 Comm: syz-executor Not tainted 4.9.0-rc5+ #54
>>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>> task: ffff880016f40480 task.stack: ffff88000fc00000
>>> RIP: 0010:[<ffffffff87a209e8>] [< inline >] rt6_get_cookie
>>> include/net/ip6_fib.h:174
>>> RIP: 0010:[<ffffffff87a209e8>] [<ffffffff87a209e8>]
>>> sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
>>> RSP: 0018:ffff88000fc07298 EFLAGS: 00010202
>>> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc900029f5000
>>> RDX: 0000000000000015 RSI: 0000000000000001 RDI: 00000000000000a8
>>> RBP: ffff88000fc07580 R08: 0000000000000000 R09: 0000000000000001
>>> R10: 0000000000000000 R11: 0000000000000000 R12: ffff880066cd0068
>>> R13: 1ffff10001f80e92 R14: ffff880066cd0040 R15: ffff88005f2d2808
>>> FS: 00007f52c41f7700(0000) GS:ffff88006d000000(0000) knlGS:0000000000000000
>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> CR2: 0000000020016000 CR3: 0000000065dd7000 CR4: 00000000000006e0
>>> DR0: 0000000000000400 DR1: 0000000000000400 DR2: 0000000000000000
>>> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
>>> Stack:
>>> ffffffff87a210f6 ffffffff8701ad45 ffff88006768ec20 ffff88006768ec20
>>> 0000000000000000 0000000016f40480 ffff88000fc07450 1ffff1000cd9a017
>>> ffff88006768ec00 ffff880066fc0730 ffff880066cd0068 1ffff10001f80e66
>>> Call Trace:
>>> [<ffffffff879a313d>] sctp_transport_route+0xad/0x430 net/sctp/transport.c:279
>>> [<ffffffff8799b106>] sctp_assoc_add_peer+0x5a6/0x13e0 net/sctp/associola.c:641
>>> [<ffffffff879e8911>] sctp_sendmsg+0x1921/0x3bc0 net/sctp/socket.c:1864
>>> [<ffffffff8701ad45>] inet_sendmsg+0x385/0x590 net/ipv4/af_inet.c:734
>>> [< inline >] sock_sendmsg_nosec net/socket.c:621
>>> [<ffffffff86a6d54f>] sock_sendmsg+0xcf/0x110 net/socket.c:631
>>> [<ffffffff86a6ede0>] SYSC_sendto+0x660/0x810 net/socket.c:1656
>>> [<ffffffff86a71dd5>] SyS_sendto+0x45/0x60 net/socket.c:1624
>>> [<ffffffff88149dc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
>>> Code: 00 00 48 8b 84 24 88 00 00 00 48 8b 58 40 e8 80 76 cc f9 48 8d
>>> bb a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80>
>>> 3c 02 00 0f 85 56 0f 00 00 48 8b 9b a8 00 00 00 45 31 ed 48
>>> RIP [< inline >] rt6_get_cookie include/net/ip6_fib.h:174
>>> RIP [<ffffffff87a209e8>] sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
>>> RSP <ffff88000fc07298>
>>> ---[ end trace b8d1354fa571700d ]---
>>>
>>>
>>> general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
>>> Dumping ftrace buffer:
>>> (ftrace buffer empty)
>>> Modules linked in:
>>> CPU: 3 PID: 22744 Comm: syz-executor Not tainted 4.9.0-rc5+ #54
>>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>> task: ffff88006b92a840 task.stack: ffff88006a730000
>>> RIP: 0010:[<ffffffff87a209e8>] [< inline >] rt6_get_cookie
>>> include/net/ip6_fib.h:174
>>> RIP: 0010:[<ffffffff87a209e8>] [<ffffffff87a209e8>]
>>> sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
>>> RSP: 0018:ffff88006a736b88 EFLAGS: 00010202
>>> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90003c4f000
>>> RDX: 0000000000000015 RSI: 0000000000000001 RDI: 00000000000000a8
>>> RBP: ffff88006a736e68 R08: 0000000000000000 R09: 0000000000000001
>>> R10: 0000000000000000 R11: 0000000000000000 R12: ffff880064cff268
>>> R13: 1ffff1000d4e6db0 R14: ffff880064cff240 R15: ffff88006a4b6808
>>> FS: 00007f74f4ec9700(0000) GS:ffff88006d100000(0000) knlGS:0000000000000000
>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> CR2: 000000002070effc CR3: 000000003bd2f000 CR4: 00000000000006e0
>>> DR0: 0000000000000400 DR1: 0000000000000400 DR2: 0000000000000000
>>> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
>>> Stack:
>>> ffffffff87a210f6 ffffffff000bbd2d ffff88006c2cd5a0 ffff88006c2cd5a0
>>> 0000000000000000 000000006ccb46c0 ffff88006a736d40 1ffff1000c99fe57
>>> ffff88006c2cd500 ffff8800658b1f30 ffff880064cff268 1ffff1000d4e6d84
>>> Call Trace:
>>> [<ffffffff879a313d>] sctp_transport_route+0xad/0x430 net/sctp/transport.c:279
>>> [<ffffffff8799b106>] sctp_assoc_add_peer+0x5a6/0x13e0 net/sctp/associola.c:641
>>> [<ffffffff879e4358>] __sctp_connect+0x288/0xc90 net/sctp/socket.c:1178
>>> [<ffffffff879e4f0b>] __sctp_setsockopt_connectx+0x1ab/0x200
>>> net/sctp/socket.c:1332
>>> [< inline >] sctp_getsockopt_connectx3 net/sctp/socket.c:1417
>>> [<ffffffff879fd2bd>] sctp_getsockopt+0x36ed/0x6800 net/sctp/socket.c:6474
>>> [<ffffffff86a76c0a>] sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:2649
>>> [< inline >] SYSC_getsockopt net/socket.c:1788
>>> [<ffffffff86a724d7>] SyS_getsockopt+0x257/0x390 net/socket.c:1770
>>> [<ffffffff88149dc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
>>> Code: 00 00 48 8b 84 24 88 00 00 00 48 8b 58 40 e8 80 76 cc f9 48 8d
>>> bb a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80>
>>> 3c 02 00 0f 85 56 0f 00 00 48 8b 9b a8 00 00 00 45 31 ed 48
>>> RIP [< inline >] rt6_get_cookie include/net/ip6_fib.h:174
>>> RIP [<ffffffff87a209e8>] sctp_v6_get_dst+0x7c8/0x1960 net/sctp/ipv6.c:340
>>> RSP <ffff88006a736b88>
>>> ---[ end trace f42d1c14cb6d2835 ]---
>>>
>>> This happened on commit a25f0944ba9b1d8a6813fd6f1a86f1bd59ac25a6 (Nov 13).
>>>
>>> Unfortunately this is not reproducible.
>>>
>>> The line is:
>>>
>>> return rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
>>>
>>> Can it be a data race? rt->rt6i_node != NULL, but the next moment it
>>> is already NULL? That would explain the crash and non-reproducibility
>>> (need ThreadSanitizer!).
>>>
>>> This always happened when called from sctp code, but I don't know if
>>> it is relevant or not. It happened only 3 times.
>>
>> I'm seeing similar crashes from ipv6 and dccp code, reports below.
>>
>> [...]
>
> Thanks for the report.
>
> Do you have a thread running that concurrently mutates the routing table?
Hi Hannes,
We're running a fuzzer which calls random system calls from multiple
processes simultaneously, so it's quite possible.
Thanks!
>
> Bye,
> Hannes
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-11-30 11:10 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-11-26 16:23 net: GPF in rt6_get_cookie Dmitry Vyukov
2016-11-30 10:39 ` Andrey Konovalov
2016-11-30 11:00 ` Hannes Frederic Sowa
2016-11-30 11:10 ` Andrey Konovalov
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).