Hi!
After a big break I continued testing the bug. I took one real machine
and a
netfilter rule to always respond with ICMP "protocol unreachable". This
is as
follows:
iptables -A INPUT -p sctp --dport 12345 -j REJECT --reject-with \
icmp-proto-unreachable
Then I start the following program to repetitive connect to
localhost:12345
and shutdown again.
/*BEGIN*/
#include <netinet/in.h>
#include <string.h>
#include <stdio.h>
#include <netinet/sctp.h>
#define _RUNS_ 100
#define _CONNECT_PORT_ 12345
#define _ERROR(a) { \
perror(a); \
return 1; \
}
int test()
{
int sock;
struct sockaddr_in sin_bind, sin_connect;
struct sctp_initmsg init;
/* create socket */
if((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_SCTP)) < 0)
_ERROR("socket");
/* bind socket */
memset(&sin_bind, 0, sizeof(struct sockaddr_in));
sin_bind.sin_family = AF_INET;
sin_bind.sin_addr.s_addr = INADDR_ANY;
if(bind(sock, (struct sockaddr*)&sin_bind, sizeof(struct
sockaddr_in)))
_ERROR("bind");
/* set sctp options */
init.sinit_num_ostreams = 1;
init.sinit_max_instreams = 1;
init.sinit_max_attempts = 1;
init.sinit_max_init_timeo = 1;
if(setsockopt(sock, IPPROTO_SCTP, SCTP_INITMSG, &init,
sizeof(struct sctp_initmsg)))
_ERROR("setsockopt");
/* connect */
memset(&sin_connect, 0, sizeof(struct sockaddr_in));
sin_connect.sin_family = AF_INET;
sin_connect.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
sin_connect.sin_port = htons( _CONNECT_PORT_ );
if(connect(sock, (struct sockaddr*)&sin_connect, sizeof(struct
sockaddr_in)))
_ERROR("connect");
/* shutdown socket */
if(shutdown(sock, 2))
_ERROR("shutdown");
return 0;
}
int main(int argc, char** argv)
{
int i, ret;
for(i=0; i< _RUNS_ ; i++)
ret = test();
return 0;
}
/* END */
The initiation seems to be very important while its values don't. I
launched
the program once and waited a few seconds for the sctp module to crash.
I hope
this time your machine crashes too ;-)
This time I tested on a real machine with Debian Lenny (linux 2.6.26
debian
kernel) and a virtual machine with linux 2.6.32.3. Both crashed.
Regards,
Michael
-----Original Message-----
From: linux-sctp-owner@xxxxxxxxxxxxxxx
[mailto:linux-sctp-owner@xxxxxxxxxxxxxxx] On Behalf Of Michael
Krolikowski
Sent: Mittwoch, 30. September 2009 18:02
To: Vlad Yasevich
Cc: linux-sctp@xxxxxxxxxxxxxxx
Subject: RE: linux sctp bug
sctp_test -H 192.168.123.2 -P 12345 -h 192.168.123.3 -p 2345 -s
where 192.168.123.2 is the host which crashes and 192.168.123.3
The host which sends ICMP messages.
Michael
-----Original Message-----
From: Vlad Yasevich [mailto:vladislav.yasevich@xxxxxx]
Sent: Mittwoch, 30. September 2009 17:58
To: Michael Krolikowski
Cc: linux-sctp@xxxxxxxxxxxxxxx
Subject: Re: linux sctp bug
Michael Krolikowski wrote:
> I've first seen the bug in Debian Lenny with Debian's patched Linux
2.6.
> Now I've just installed Linux 2.6.26.8 (UML) and seen a different
> behavior:
>
> SCTP: Hash tables configured (established 512 bind 512)
> BUG: soft lockup - CPU#0 stuck for 61s! [sctp_test:847]
> Modules linked in: sctp
>
> Modules linked in: sctp
> Pid: 847, comm: sctp_test Not tainted 2.6.26.8
> RIP: 0033:[<0000000062dad9c2>]
> RSP: 0000000061f3b870 EFLAGS: 00000202
> RAX: 7360adde2c000001 RBX: 0000000061e20000 RCX: 0000000061f3b910
> RDX: 7360adde2c000001 RSI: 0000000000000000 RDI: 000000006150ea00
> RBP: 0000000061f3b880 R08: 0000000061e20140 R09: 0000000000000000
> R10: 0000000060228240 R11: 0000000000000049 R12: 0000000061e20000
> R13: 0000000061e20000 R14: 0000000062dbfeb5 R15: 0000000062dc1a00
> Call Trace:
> 601c7ae8: [<6004e355>] softlockup_tick+0xf7/0x10a
> 601c7af8: [<600318e7>] raise_softirq+0x64/0x6d
> 601c7b28: [<60035bf0>] run_local_timers+0x18/0x1a
> 601c7b38: [<60035c69>] update_process_times+0x2e/0x59
> 601c7b68: [<600463c9>] tick_sched_timer+0x64/0x96
> 601c7b98: [<600418da>] __run_hrtimer+0x26/0x6f
> 601c7bb8: [<600421b2>] hrtimer_interrupt+0xe3/0x143
> 601c7bf8: [<60012cd4>] um_timer+0xf/0x16
> 601c7c08: [<6004e78a>] handle_IRQ_event+0x2b/0x5f
> 601c7c38: [<6004e81f>] __do_IRQ+0x61/0xa6
> 601c7c68: [<60010b8a>] do_IRQ+0x23/0x39
> 601c7c88: [<60012d42>] timer_handler+0x21/0x2f
> 601c7ca8: [<60020e87>] real_alarm_handler+0x3f/0x41
> 601c7cb8: [<62dbfeb5>] sctp_pname+0x0/0x1a [sctp]
> 601c7d30: [<62dad9c2>] sctp_assoc_update_retran_path+0x44/0x13e
[sctp]
> 601c7db8: [<60020ee5>] alarm_handler+0x2e/0x39
> 601c7dd8: [<60021179>] handle_signal+0x6b/0xa1
> 601c7e10: [<62dbfeb5>] sctp_pname+0x0/0x1a [sctp]
> 601c7e28: [<60022a90>] hard_handler+0x10/0x14
> 601c7e98: [<62dbfeb5>] sctp_pname+0x0/0x1a [sctp]
> 601c7ee8: [<62dad9c2>] sctp_assoc_update_retran_path+0x44/0x13e
[sctp]
>
> I did the test with the sctp_test tool from http://lksctp.sf.net/
> I just repeated executing the tool manually, so no tight loop.
Can you provide the command line args you use? Want to try it in my KVM
sessions.
-vlad
> I always had both systems running with the same Linux Version. But
this
> shouldn't be the problem should it? It's always the same ICMP message
I
> get
> from the remote host.
> I did the test with Debian Lenny running inside VMware as well but
> didn't
> test inside KVM. I couldn't reproduce the bug in live systems but I
did
> only one quick test there. I'll give that a try and let you know - but
> it
> might take me a while.
>
> Michael
>
>
> -----Original Message-----
> From: Vlad Yasevich [mailto:vladislav.yasevich@xxxxxx]
> Sent: Mittwoch, 30. September 2009 16:31
> To: Michael Krolikowski
> Cc: linux-sctp@xxxxxxxxxxxxxxx
> Subject: Re: linux sctp bug
>
> Michael Krolikowski wrote:
>> Hi,
>>
>> I'm testing it using two UML machines. Both of them running Linux
>> 2.6.31.
>> I tried it today again and it seems that the error occurs not as I
> first
>> said after only a few tries but many tries later it does.
>> I also tried with 2.6.31.1 (UML) with the same results.
>> I used Debian Lenny with a 2.6.26 Linux where I got the error for the
>> first time.
>
> So you were able to reproduce this with 2.6.26 kernel?
>
> How do you test? Do you just try to call connect() in a loop?
>
> I run under KVM with a connect() call in a tight loop and see
> not issues. My ICMP sender is an Ubuntu Jaunty (2.6.28-15-generic)
> kernel.
>
> Looking at the stack trace you posted, the failure happens here:
> if (!asoc->temp) {
>>>> list_del(&asoc->asocs);
>
> The addresses look very weird to.
>
> Can reproduce this with live systems, or KVM? I am suspecting UML...
>
> -vlad
>
>
>> I hope this little information helps you a bit.
>>
>>
>> Regards,
>>
>> Michael
>>
>>
>> -----Original Message-----
>> From: Vlad Yasevich [mailto:vladislav.yasevich@xxxxxx]
>> Sent: Montag, 28. September 2009 18:46
>> To: Michael Krolikowski
>> Cc: Sridhar Samudrala; Linux SCTP Dev Mailing list
>> Subject: Re: linux sctp bug
>>
>> Michael Krolikowski wrote:
>>> Hi,
>>>
>>> I think I found a bug in the Linux SCTP implementation. I hope you
> are
>>> the right persons to ask for help with this.
>> The right place to ask is on linux-sctp mailing list.
>>
>>> If I send an SCTP INIT to a host which does not support SCTP (e.g.
> the
>>> module is not loaded), the
>>> other host sends an ICMP Protocol unreachable. This makes the SCTP
>>> module on the initiating host
>>> crash. It maybe that it crashes not at the first try but if I repeat
>> the
>>> SCTP INIT 3-4 times it will crash.
>> Hm.. I've tried to reproduce and couldn't with top of tree 2.6.31.
>> I've tried repeating INITs over the same path and over multiple
paths,
>> but
>> didn't see a crash.
>>
>> Would you be able to do a bisect?
>>
>> Thanks
>> -vlad
>>
>>> See this message:
>>> SCTP: Hash tables configured (established 512 bind 512)
>>>
>>> Modules linked in: sctp
>>> Pid: 610, comm: sctp_test Not tainted 2.6.31
>>> RIP: 0033:[<00000000646228f9>]
>>> RSP: 0000000063873810 EFLAGS: 00010246
>>> RAX: 0000000000200200 RBX: 0000000063a20000 RCX: 00000000638e6800
>>> RDX: 0000000000100100 RSI: 000000006384b8c0 RDI: 0000000063a20000
>>> RBP: 0000000063873830 R08: 0000003000000008 R09: 0000000000000000
>>> R10: 000000000000000f R11: 0000000000000000 R12: 00000000ffffffea
>>> R13: 00000000638e6800 R14: 0000000063a20000 R15: 0000000063a20000
>>> Call Trace:
>>> 601f1ad8: [<60014bcd>] segv+0x1fd/0x20f
>>> 601f1b18: [<601102f0>] process_backlog+0x8b/0xa9
>>> 601f1b58: [<60110904>] net_rx_action+0xe5/0x123
>>> 601f1bb8: [<60014c92>] segv_handler+0xb3/0xb9
>>> 601f1bf8: [<600329c4>] do_softirq+0x43/0x4a
>>> 601f1c28: [<60016439>] free_irqs+0x72/0xd4
>>> 601f1c68: [<60012108>] sigio_handler+0x5a/0x5f
>>> 601f1c88: [<60021a47>] sig_handler_common+0x87/0x9b
>>> 601f1d10: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>> 601f1d30: [<60017b51>] line_write_room+0x57/0x58
>>> 601f1db8: [<60021b90>] sig_handler+0x30/0x3b
>>> 601f1dd8: [<60021de9>] handle_signal+0x6b/0xa1
>>> 601f1e28: [<600236fc>] hard_handler+0x10/0x14
>>> 601f1ee8: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>>
>>> Kernel panic - not syncing: Kernel mode fault at addr 0x100108, ip
>>> 0x646228f9
>>> Call Trace:
>>> 601f19d8: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>> 601f19e8: [<60158b8d>] panic+0xd3/0x174
>>> 601f1a20: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>> 601f1a40: [<6004c462>] __module_text_address+0xd/0x5b
>>> 601f1a58: [<6004c4b9>] is_module_text_address+0x9/0x11
>>> 601f1a68: [<6003e264>] __kernel_text_address+0x65/0x6b
>>> 601f1a70: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>> 601f1a88: [<60013a96>] show_trace+0x8e/0x92
>>> 601f1aa8: [<600271ff>] show_regs+0x2b/0x30
>>> 601f1ad8: [<60014bdf>] segv_handler+0x0/0xb9
>>> 601f1b18: [<601102f0>] process_backlog+0x8b/0xa9
>>> 601f1b58: [<60110904>] net_rx_action+0xe5/0x123
>>> 601f1bb8: [<60014c92>] segv_handler+0xb3/0xb9
>>> 601f1bf8: [<600329c4>] do_softirq+0x43/0x4a
>>> 601f1c28: [<60016439>] free_irqs+0x72/0xd4
>>> 601f1c68: [<60012108>] sigio_handler+0x5a/0x5f
>>> 601f1c88: [<60021a47>] sig_handler_common+0x87/0x9b
>>> 601f1d10: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>> 601f1d30: [<60017b51>] line_write_room+0x57/0x58
>>> 601f1db8: [<60021b90>] sig_handler+0x30/0x3b
>>> 601f1dd8: [<60021de9>] handle_signal+0x6b/0xa1
>>> 601f1e28: [<600236fc>] hard_handler+0x10/0x14
>>> 601f1ee8: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>>
>>>
>>> Modules linked in: sctp
>>> Pid: 610, comm: sctp_test Not tainted 2.6.31
>>> RIP: 0033:[<00000000404ef5c0>]
>>> RSP: 0000007fbf8613f8 EFLAGS: 00000246
>>> RAX: ffffffffffffffda RBX: 0000007fbf861460 RCX: ffffffffffffffff
>>> RDX: 0000000000000100 RSI: 0000007fbf861410 RDI: 0000000000000003
>>> RBP: 0000000000000001 R08: 00000000ffffffff R09: 0000000000000000
>>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000607560
>>> R13: 0000000000000002 R14: 0000000000000000 R15: 0000007fbf861450
>>> Call Trace:
>>> 601f1960: [<6004c462>] __module_text_address+0xd/0x5b
>>> 601f1978: [<60014e05>] panic_exit+0x2f/0x45
>>> 601f1998: [<60043417>] notifier_call_chain+0x33/0x5b
>>> 601f19c8: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>> 601f19d8: [<60043459>] atomic_notifier_call_chain+0xf/0x11
>>> 601f19e8: [<60158b9e>] panic+0xe4/0x174
>>> 601f1a20: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>> 601f1a40: [<6004c462>] __module_text_address+0xd/0x5b
>>> 601f1a58: [<6004c4b9>] is_module_text_address+0x9/0x11
>>> 601f1a68: [<6003e264>] __kernel_text_address+0x65/0x6b
>>> 601f1a70: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>> 601f1a88: [<60013a96>] show_trace+0x8e/0x92
>>> 601f1aa8: [<600271ff>] show_regs+0x2b/0x30
>>> 601f1ad8: [<60014bdf>] segv_handler+0x0/0xb9
>>> 601f1b18: [<601102f0>] process_backlog+0x8b/0xa9
>>> 601f1b58: [<60110904>] net_rx_action+0xe5/0x123
>>> 601f1bb8: [<60014c92>] segv_handler+0xb3/0xb9
>>> 601f1bf8: [<600329c4>] do_softirq+0x43/0x4a
>>> 601f1c28: [<60016439>] free_irqs+0x72/0xd4
>>> 601f1c68: [<60012108>] sigio_handler+0x5a/0x5f
>>> 601f1c88: [<60021a47>] sig_handler_common+0x87/0x9b
>>> 601f1d10: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>> 601f1d30: [<60017b51>] line_write_room+0x57/0x58
>>> 601f1db8: [<60021b90>] sig_handler+0x30/0x3b
>>> 601f1dd8: [<60021de9>] handle_signal+0x6b/0xa1
>>> 601f1e28: [<600236fc>] hard_handler+0x10/0x14
>>> 601f1ee8: [<646228f9>] sctp_association_free+0x2b/0x1e0 [sctp]
>>>
>>> This error seems only to occur if the remote host answers with ICMP
>>> protocol unreachable.
>>> If the remote host answers with SCTP ABORT, the error won't occur.
>>>
>>>
>>> Thanks in advance,
>>>
>>> Michael Krolikowski
>>>
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