INFO: rcu_preempt self-detected stall on CPU 1-...: (1 GPs behind) idle=e1e/140000000000002/0 softirq=98540/98542 fqs=0 (t=10500 jiffies g=27009 c=27008 q=58) rcu_preempt kthread starved for 10500 jiffies! g27009 c27008 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 rcu_preempt R running task 29408 8 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3384 schedule+0x92/0x1c0 kernel/sched/core.c:3428 schedule_timeout+0x43e/0xe10 kernel/time/timer.c:1746 rcu_gp_kthread+0xbf4/0x1ec0 kernel/rcu/tree.c:2255 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 NMI backtrace for cpu 1 CPU: 1 PID: 6995 Comm: syz-executor.5 Not tainted 4.14.171-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x142/0x197 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 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:158 [inline] rcu_dump_cpu_stacks+0x186/0x1d2 kernel/rcu/tree.c:1396 print_cpu_stall kernel/rcu/tree.c:1542 [inline] check_cpu_stall kernel/rcu/tree.c:1610 [inline] __rcu_pending kernel/rcu/tree.c:3390 [inline] rcu_pending kernel/rcu/tree.c:3452 [inline] rcu_check_callbacks.cold+0x43d/0xd0a kernel/rcu/tree.c:2792 update_process_times+0x31/0x70 kernel/time/timer.c:1590 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:165 tick_sched_timer+0x43/0x130 kernel/time/tick-sched.c:1223 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x270/0xbc0 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1d8/0x5d0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x11c/0x5e0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:142 [inline] RIP: 0010:__dev_queue_xmit+0x688/0x25e0 net/core/dev.c:3473 RSP: 0018:ffff8880aed07300 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000000 RBX: ffff888092a3b040 RCX: ffff888099eefecc RDX: 1ffff110133ddfd2 RSI: ffff888099eefe28 RDI: ffff888099eefe90 RBP: ffff8880aed07450 R08: ffffffff851e02c2 R09: ffff88808b45ed68 R10: ffff88808b45ed48 R11: ffff88808b45e400 R12: ffff888099eefe00 R13: ffff888099eefec6 R14: 0000000000000062 R15: ffff888092a3ad80 dev_queue_xmit+0x18/0x20 net/core/dev.c:3558 neigh_hh_output include/net/neighbour.h:490 [inline] neigh_output include/net/neighbour.h:498 [inline] ip_finish_output2+0xde8/0x14a0 net/ipv4/ip_output.c:229 ip_finish_output+0x56d/0xc60 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:239 [inline] ip_output+0x1e6/0x590 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:462 [inline] ip_local_out+0x97/0x170 net/ipv4/ip_output.c:124 ip_queue_xmit+0x7d7/0x1b10 net/ipv4/ip_output.c:504 sctp_v4_xmit+0x109/0x140 net/sctp/protocol.c:996 sctp_packet_transmit+0x199e/0x3010 net/sctp/output.c:637 sctp_outq_flush+0xd13/0x31b0 net/sctp/outqueue.c:1187 sctp_outq_uncork+0x60/0x70 net/sctp/outqueue.c:761 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1787 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1179 [inline] sctp_do_sm+0x452/0x50d0 net/sctp/sm_sideeffect.c:1150 sctp_generate_heartbeat_event+0x1dd/0x400 net/sctp/sm_sideeffect.c:391 call_timer_fn+0x161/0x670 kernel/time/timer.c:1279 expire_timers kernel/time/timer.c:1318 [inline] __run_timers kernel/time/timer.c:1636 [inline] __run_timers kernel/time/timer.c:1604 [inline] run_timer_softirq+0x5b7/0x1520 kernel/time/timer.c:1649 __do_softirq+0x244/0x9a0 kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x160/0x1b0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x146/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:lock_acquire+0x1ea/0x430 kernel/locking/lockdep.c:3997 RSP: 0018:ffff88802799f858 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff0fe2cc9 RBX: ffff88808b45e400 RCX: 0000000000ee85a7 RDX: dffffc0000000000 RSI: ffff88808b45ec80 RDI: 0000000000000282 RBP: ffff88802799f8a0 R08: 0000000000004993 R09: ffffffff89573518 R10: ffff88808b45ec80 R11: ffff88808b45e400 R12: ffff8880a6ce54d0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 down_write+0x38/0x90 kernel/locking/rwsem.c:54 i_mmap_lock_write include/linux/fs.h:473 [inline] unlink_file_vma+0x76/0xb0 mm/mmap.c:152 free_pgtables+0x18b/0x2b0 mm/memory.c:644 exit_mmap+0x294/0x4e0 mm/mmap.c:3057 __mmput kernel/fork.c:930 [inline] mmput+0x114/0x440 kernel/fork.c:951 exit_mm kernel/exit.c:545 [inline] do_exit+0x952/0x2cd0 kernel/exit.c:845 do_group_exit+0x111/0x330 kernel/exit.c:955 get_signal+0x381/0x1cd0 kernel/signal.c:2418 do_signal+0x86/0x19a0 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x15c/0x220 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c429 RSP: 002b:00007f070722bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 0000000000000023 RBX: 00007f070722c6d4 RCX: 000000000045c429 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000004 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000009f2 R14: 00000000004cc667 R15: 000000000076bf2c