On Wed, May 16, 2018 at 1:02 PM, Xin Long <lucien.xin@xxxxxxxxx> wrote: >>> <syzbot+ff0b569fb5111dcd1a36@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: >>>> Hello, >>>> >>>> syzbot found the following crash on: >>>> >>>> HEAD commit: 961423f9fcbc Merge branch 'sctp-Introduce-sctp_flush_ctx' >>>> git tree: net-next >>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1366aea7800000 >>>> kernel config: https://syzkaller.appspot.com/x/.config?x=51fb0a6913f757db >>>> dashboard link: https://syzkaller.appspot.com/bug?extid=ff0b569fb5111dcd1a36 >>>> compiler: gcc (GCC) 8.0.1 20180413 (experimental) >>>> >>>> Unfortunately, I don't have any reproducer for this crash yet. >>>> >>>> IMPORTANT: if you fix the bug, please add the following tag to the commit: >>>> Reported-by: syzbot+ff0b569fb5111dcd1a36@xxxxxxxxxxxxxxxxxxxxxxxxx >>>> >>>> INFO: rcu_sched self-detected stall on CPU >>>> 0-....: (1 GPs behind) idle=dae/1/4611686018427387908 >>>> softirq=93090/93091 fqs=30902 >>>> (t=125000 jiffies g=51107 c=51106 q=972) >>>> NMI backtrace for cpu 0 >>>> CPU: 0 PID: 24668 Comm: syz-executor6 Not tainted 4.17.0-rc4+ #44 >>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >>>> Google 01/01/2011 >>>> Call Trace: >>>> <IRQ> >>>> __dump_stack lib/dump_stack.c:77 [inline] >>>> dump_stack+0x1b9/0x294 lib/dump_stack.c:113 >>>> nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 >>>> nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 >>>> arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 >>>> trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline] >>>> rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1376 >>>> print_cpu_stall kernel/rcu/tree.c:1525 [inline] >>>> check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593 >>>> __rcu_pending kernel/rcu/tree.c:3356 [inline] >>>> rcu_pending kernel/rcu/tree.c:3401 [inline] >>>> rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763 >>>> update_process_times+0x2d/0x70 kernel/time/timer.c:1636 >>>> tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164 >>>> tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274 >>>> __run_hrtimer kernel/time/hrtimer.c:1398 [inline] >>>> __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1460 >>>> hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518 >>>> local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] >>>> smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050 >>>> apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863 >>>> RIP: 0010:sctp_v6_xmit+0x259/0x6b0 net/sctp/ipv6.c:219 >>>> RSP: 0018:ffff8801dae068e8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 >>>> RAX: 0000000000000007 RBX: ffff8801bb7ec800 RCX: ffffffff86f1b345 >>>> RDX: 0000000000000000 RSI: ffffffff86f1b381 RDI: ffff8801b73d97c4 >>>> RBP: ffff8801dae06988 R08: ffff88019505c300 R09: ffffed003b5c46c2 >>>> R10: ffffed003b5c46c2 R11: ffff8801dae23613 R12: ffff88011fd57300 >>>> R13: ffff8801bb7ecec8 R14: 0000000000000029 R15: 0000000000000002 >>>> sctp_packet_transmit+0x26f6/0x3ba0 net/sctp/output.c:642 >>>> sctp_outq_flush_transports net/sctp/outqueue.c:1164 [inline] >>>> sctp_outq_flush+0x5f5/0x3430 net/sctp/outqueue.c:1212 >>>> sctp_outq_uncork+0x6a/0x80 net/sctp/outqueue.c:776 >>>> sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1820 [inline] >>>> sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline] >>>> sctp_do_sm+0x596/0x7160 net/sctp/sm_sideeffect.c:1191 >>>> sctp_generate_heartbeat_event+0x218/0x450 net/sctp/sm_sideeffect.c:406 >>> Shocks, this timer event again. Can we try to minimize the repo.syz and >>> get a short script, not neccessary to reproduce the issue 100%. we need >>> to know what it was doing when this happened. >>> >>> Thanks. >> >> It's possible to reply the whole log from console output following >> these instructions: >> https://github.com/google/syzkaller/blob/master/docs/executing_syzkaller_programs.md > Thanks, it's running now. > Usually how long will it take to finish running this 5000-line log? If you run with -repeat=0 then it will run infinitely repeating the log again and again. If you see: parsed 1000 programs ... executed 5000 programs then it looped 5 times already. You can run with -repeat=10. syzbot has tried replaying the log, but for some reason it wasn't able to reproduce the crash (maybe accumulated state, or maybe it crashed in a different way). You can also try logs from other sctp hangs. -- 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
