Re: INFO: rcu detected stall in save_stack_trace

[Dmitry Vyukov]

On Mon, May 21, 2018 at 7:25 PM, syzbot
<syzbot+0f775f734aa841af54cc@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    0b449a441dac Merge tag 'dmaengine-fix-4.17-rc6' of git://g..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=127ec337800000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=f3b4e30da84ec1ed
> dashboard link: https://syzkaller.appspot.com/bug?extid=0f775f734aa841af54cc
> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=17d3a84f800000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10770827800000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+0f775f734aa841af54cc@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> 8021q: adding VLAN 0 to HW filter on device team0
> 8021q: adding VLAN 0 to HW filter on device team0
> 8021q: adding VLAN 0 to HW filter on device team0
> 8021q: adding VLAN 0 to HW filter on device team0
> 8021q: adding VLAN 0 to HW filter on device team0
> INFO: rcu_sched self-detected stall on CPU
>         0-...!: (124935 ticks this GP) idle=042/1/4611686018427387908
> softirq=14940/14940 fqs=5
>          (t=125000 jiffies g=7464 c=7463 q=430266)
> NMI backtrace for cpu 0
> CPU: 0 PID: 6412 Comm: ip Not tainted 4.17.0-rc5+ #59
> 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:__save_stack_trace+0x53/0xd0 arch/x86/kernel/stacktrace.c:43
> RSP: 0018:ffff8801dae06ce0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
> RAX: ffffffff85da28ea RBX: ffff8801dae06d78 RCX: 0000000000000001
> RDX: 1ffff1003b5c0da5 RSI: ffff8801c08b7758 RDI: ffffffff85da28ea
> RBP: ffff8801dae06d58 R08: ffff8801dae06d18 R09: ffff8801c0a62180
> R10: ffffed003b5c0da6 R11: ffff8801dae06d37 R12: 0000000000000000
> R13: 0000000000000000 R14: ffff8801c0a62180 R15: ffff88007c262427
>  save_stack_trace+0x1a/0x20 arch/x86/kernel/stacktrace.c:60
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
>  set_track mm/kasan/kasan.c:460 [inline]
>  kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
>  kmem_cache_alloc_node+0x144/0x780 mm/slab.c:3644
>  __alloc_skb+0x111/0x780 net/core/skbuff.c:193
>  alloc_skb include/linux/skbuff.h:987 [inline]
>  _sctp_make_chunk+0x58/0x280 net/sctp/sm_make_chunk.c:1417
>  sctp_make_control net/sctp/sm_make_chunk.c:1464 [inline]
>  sctp_make_heartbeat+0x8f/0x430 net/sctp/sm_make_chunk.c:1177
>  sctp_sf_heartbeat.isra.23+0x26/0x180 net/sctp/sm_statefuns.c:1005
>  sctp_sf_sendbeat_8_3+0x38e/0x550 net/sctp/sm_statefuns.c:1049
>  sctp_do_sm+0x1ab/0x7160 net/sctp/sm_sideeffect.c:1188
>  sctp_generate_heartbeat_event+0x218/0x450 net/sctp/sm_sideeffect.c:406
>  call_timer_fn+0x230/0x940 kernel/time/timer.c:1326
>  expire_timers kernel/time/timer.c:1363 [inline]
>  __run_timers+0x79e/0xc50 kernel/time/timer.c:1666
>  run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692
>  __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
>  invoke_softirq kernel/softirq.c:365 [inline]
>  irq_exit+0x1d1/0x200 kernel/softirq.c:405
>  exiting_irq arch/x86/include/asm/apic.h:525 [inline]
>  smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052
>  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
>  </IRQ>
> RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783
> [inline]
> RIP: 0010:kmem_cache_free+0xb3/0x2d0 mm/slab.c:3757
> RSP: 0018:ffff8801c08b7568 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
> RAX: 0000000000000007 RBX: ffff8801bb77f300 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000286
> RBP: ffff8801c08b7588 R08: ffff8801c08b7310 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d9bdd6c0
> R13: 0000000000000286 R14: ffffffff85d7708c R15: 0000000000000000
>  kfree_skbmem+0x13c/0x210 net/core/skbuff.c:582
>  __kfree_skb net/core/skbuff.c:642 [inline]
>  consume_skb+0x193/0x550 net/core/skbuff.c:701
>  skb_free_datagram+0x1a/0xf0 net/core/datagram.c:329
>  netlink_recvmsg+0x6fe/0x1450 net/netlink/af_netlink.c:1980
>  sock_recvmsg_nosec net/socket.c:802 [inline]
>  sock_recvmsg+0xd0/0x110 net/socket.c:809
>  ___sys_recvmsg+0x2b6/0x680 net/socket.c:2279
>  __sys_recvmsg+0x112/0x260 net/socket.c:2328
>  __do_sys_recvmsg net/socket.c:2338 [inline]
>  __se_sys_recvmsg net/socket.c:2335 [inline]
>  __x64_sys_recvmsg+0x78/0xb0 net/socket.c:2335
>  do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
>  entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x7f8daae3a210
> RSP: 002b:00007fff88d0a008 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8daae3a210
> RDX: 0000000000000000 RSI: 00007fff88d0a050 RDI: 0000000000000003
> RBP: 0000000000003b38 R08: 00007f8dab0e3ec8 R09: 00007f8daae80c00
> R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006395c0
> R13: 00007fff88d0e0e0 R14: 0000000000003b38 R15: 00007fff88d0dbc8

#syz fix: sctp: not allow to set rto_min with a value below 200 msecs

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