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. 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 >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
