Subject: INFO: rcu detected stall in corrupted

From: syzbot <[email-masked]>
Date: Mon, 21 May 2018 11:05:02 -0700

Hello,

syzbot found the following crash on:

HEAD commit:    771c577c23ba Linux 4.17-rc6
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17134357800000
kernel config:  https://syzkaller.appspot.com/x/.config?x=982e2df1b9e60b02
dashboard link: https://syzkaller.appspot.com/bug?extid=f116bc1994efe725d51b
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
userspace arch: i386
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=14e5a7cf800000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email-masked]

IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
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
INFO: rcu_sched detected stalls on CPUs/tasks:
	0-...!: (124975 ticks this GP) idle=a36/1/4611686018427387906  
softirq=14002/14002 fqs=10
	
	0-...!: (124975 ticks this GP) idle=a36/1/4611686018427387906  
softirq=14002/14002 fqs=10
	
  (t=125002 jiffies g=7347 c=7346 q=349000)
(detected by 1, t=125002 jiffies, g=7347, c=7346, q=349000)
rcu_sched kthread starved for 124927 jiffies! g7347 c7346 f0x2  
RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1
Sending NMI from CPU 1 to CPUs 0:
RCU grace-period kthread stack dump:
NMI backtrace for cpu 0
CPU: 0 PID: 8 Comm: ksoftirqd/0 Not tainted 4.17.0-rc6+ #86
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data+0xa/0x70 kernel/kcov.c:121
RSP: 0018:ffff8801dae06d30 EFLAGS: 00000006
RAX: 0000000000010105 RBX: 0000000000000006 RCX: ffffffff876bdc58
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001
RBP: ffff8801dae06d68 R08: ffff8801d9a9c200 R09: fffffbfff14da4bc
R10: fffffbfff14da4bc R11: ffffffff8a6d25e0 R12: ffffffff88644220
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000008
FS:  0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f595e194270 CR3: 00000001b09c2000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  <IRQ>
  vsnprintf+0x1b8/0x1b40 lib/vsprintf.c:2252
  sprintf+0xa7/0xd0 lib/vsprintf.c:2498
  print_time kernel/printk/printk.c:1223 [inline]
  print_prefix+0x26a/0x3f0 kernel/printk/printk.c:1246
  msg_print_text+0xca/0x1c0 kernel/printk/printk.c:1273
  console_unlock+0x4f5/0x1100 kernel/printk/printk.c:2369
  vprintk_emit+0x6ad/0xdd0 kernel/printk/printk.c:1907
  vprintk_default+0x28/0x30 kernel/printk/printk.c:1947
  vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:379
  printk+0x9e/0xba kernel/printk/printk.c:1980
  rcu_check_gp_kthread_starvation+0x325/0x3a4 kernel/rcu/tree.c:1353
  print_cpu_stall kernel/rcu/tree.c:1523 [inline]
  check_cpu_stall.isra.61.cold.80+0x364/0x59a 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
  </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x1/0x50 kernel/kcov.c:94
RSP: 0018:ffff8801d9aad680 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000103 RBX: 0000000000000002 RCX: ffffffff867e02e0
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000005
RBP: ffff8801d9aad7e0 R08: ffff8801d9a9c200 R09: ffff8801d9aadaf0
R10: ffffed003b5c46c2 R11: ffff8801dae23613 R12: ffff8801ce597c40
R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000
  find_match+0x244/0x13a0 net/ipv6/route.c:691
  find_rr_leaf net/ipv6/route.c:729 [inline]
  rt6_select net/ipv6/route.c:779 [inline]
  ip6_pol_route+0x946/0x3d40 net/ipv6/route.c:1705
  ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:1969
  fib6_rule_lookup+0x211/0x6d0 net/ipv6/fib6_rules.c:89
  ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:1997
  ip6_dst_lookup_tail+0x47b/0x1b30 net/ipv6/ip6_output.c:995
  ip6_dst_lookup_flow+0xc1/0x260 net/ipv6/ip6_output.c:1096
  sctp_v6_get_dst+0x16b4/0x20b0 net/sctp/ipv6.c:327
  sctp_transport_route+0xad/0x450 net/sctp/transport.c:293
  sctp_packet_config+0xb89/0xfd0 net/sctp/output.c:123
  sctp_outq_flush+0x79c/0x4370 net/sctp/outqueue.c:894
  ? trace_hardirqs_off
Lost 148 message(s)!
rcu_sched kthread starved for 124927 jiffies! g7347 c7346 f0x2  
RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1
rcu_sched       R
RCU grace-period kthread stack dump:
rcu_sched       R
   running task
   running task    23896     9      2 0x80000000
23896     9      2 0x80000000
Call Trace:
Call Trace:
  context_switch kernel/sched/core.c:2859 [inline]
  __schedule+0x801/0x1e30 kernel/sched/core.c:3501
  context_switch kernel/sched/core.c:2859 [inline]
  __schedule+0x801/0x1e30 kernel/sched/core.c:3501
  schedule+0xef/0x430 kernel/sched/core.c:3545
  schedule+0xef/0x430 kernel/sched/core.c:3545
  schedule_timeout+0x138/0x240 kernel/time/timer.c:1801
  schedule_timeout+0x138/0x240 kernel/time/timer.c:1801
  rcu_gp_kthread+0x6b5/0x1940 kernel/rcu/tree.c:2231
  rcu_gp_kthread+0x6b5/0x1940 kernel/rcu/tree.c:2231
  kthread+0x345/0x410 kernel/kthread.c:240
  kthread+0x345/0x410 kernel/kthread.c:240
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
NMI backtrace for cpu 0
CPU: 0 PID: 8 Comm: ksoftirqd/0 Not tainted 4.17.0-rc6+ #86
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
  </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x1/0x50 kernel/kcov.c:94
RSP: 0018:ffff8801d9aad680 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000103 RBX: 0000000000000002 RCX: ffffffff867e02e0
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000005
RBP: ffff8801d9aad7e0 R08: ffff8801d9a9c200 R09: ffff8801d9aadaf0
R10: ffffed003b5c46c2 R11: ffff8801dae23613 R12: ffff8801ce597c40
R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000
  find_match+0x244/0x13a0 net/ipv6/route.c:691
  find_rr_leaf net/ipv6/route.c:729 [inline]
  rt6_select net/ipv6/route.c:779 [inline]
  ip6_pol_route+0x946/0x3d40 net/ipv6/route.c:1705
  ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:1969
  fib6_rule_lookup+0x211/0x6d0 net/ipv6/fib6_rules.c:89
  ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:1997
  ip6_dst_lookup_tail+0x47b/0x1b30 net/ipv6/ip6_output.c:995
  ip6_dst_lookup_flow+0xc1/0x260 net/ipv6/ip6_output.c:1096
  sctp_v6_get_dst+0x16b4/0x20b0 net/sctp/ipv6.c:327
  sctp_transport_route+0xad/0x450 net/sctp/transport.c:293
  sctp_packet_config+0xb89/0xfd0 net/sctp/output.c:123
  sctp_outq_flush+0x79c/0x4370 net/sctp/outqueue.c:894
  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
  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
  run_ksoftirqd+0x86/0x100 kernel/softirq.c:646
  smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164
  kthread+0x345/0x410 kernel/kthread.c:240
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.929  
msecs
BUG: workqueue lockup - pool cpus=0-1 flags=0x4 nice=0 stuck for 127s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
   pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=10/256
     pending: pcpu_balance_workfn, defense_work_handler,  
defense_work_handler, defense_work_handler, defense_work_handler,  
defense_work_handler, defense_work_handler, check_corruption,  
vmstat_shepherd, cache_reap
workqueue events_power_efficient: flags=0x80
   pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
     pending: check_lifetime
workqueue mm_percpu_wq: flags=0x8
   pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
     pending: vmstat_update
workqueue writeback: flags=0x4e
   pwq 4: cpus=0-1 flags=0x4 nice=0 active=4/256
     pending: wb_workfn, wb_workfn, wb_workfn, wb_workfn
workqueue kblockd: flags=0x18
   pwq 1: cpus=0 node=0 flags=0x0 nice=-20 active=1/256
     pending: blk_mq_timeout_work
workqueue ib_addr: flags=0xa0002
   pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1
     pending: process_req
workqueue gid-cache-wq: flags=0xa0002
   pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1
     pending: update_gid_event_work_handler
     delayed: netdevice_event_work_handler
workqueue ipv6_addrconf: flags=0x40008
   pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1
     pending: addrconf_dad_work
     delayed: addrconf_dad_work, addrconf_dad_work, addrconf_dad_work,  
addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work,  
addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work,  
addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work,  
addrconf_dad_work, addrconf_dad_work, addrconf_dad_work

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