rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10501 ticks this GP) idle=6ba/1/0x4000000000000000 softirq=67469/67469 fqs=0 
	(t=10502 jiffies g=90981 q=148)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g90981 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=32855
rcu: rcu_preempt kthread starved for 10505 jiffies! g90981 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:26384 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4683 [inline]
 __schedule+0xc07/0x11f0 kernel/sched/core.c:5940
 schedule+0x14b/0x210 kernel/sched/core.c:6019
 schedule_timeout+0x1aa/0x2f0 kernel/time/timer.c:1879
 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline]
 rcu_gp_kthread+0x10fd/0x1720 kernel/rcu/tree.c:2169
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 12912 Comm: kworker/u4:7 Not tainted 5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105
 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x191/0x2f0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation+0x200/0x270 kernel/rcu/tree_stall.h:479
 print_cpu_stall kernel/rcu/tree_stall.h:623 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:700 [inline]
 rcu_pending kernel/rcu/tree.c:3922 [inline]
 rcu_sched_clock_irq+0x1d08/0x2a30 kernel/rcu/tree.c:2641
 update_process_times+0x197/0x200 kernel/time/timer.c:1783
 tick_sched_handle kernel/time/tick-sched.c:226 [inline]
 tick_sched_timer+0x27d/0x420 kernel/time/tick-sched.c:1421
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x4cb/0xa60 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:tipc_topsrv_stop net/tipc/topsrv.c:690 [inline]
RIP: 0010:tipc_topsrv_exit_net+0x115/0x310 net/tipc/topsrv.c:715
Code: e8 b0 3e 4c 00 48 89 ef e8 e8 12 00 00 4c 89 ef e8 c0 3c 4c 00 eb 13 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e8 eb 74 f0 f7 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 10 41 83 3f 00
RSP: 0018:ffffc90001a6fb30 EFLAGS: 00000293
RAX: ffffffff898fc3e5 RBX: 1ffff11005a57413 RCX: ffff88808a9ad4c0
RDX: 0000000000000000 RSI: ffffffffadf33fd7 RDI: 000000000000003f
RBP: ffff888029d3e000 R08: ffffffff842b89ea R09: 0000000000000003
R10: fffff5200034df55 R11: 0000000000000004 R12: ffff88802d2ba000
R13: ffff88802d2ba058 R14: 00000000adf33fd7 R15: ffff88802d2ba098
 ops_exit_list net/core/net_namespace.c:175 [inline]
 cleanup_net+0x758/0xc60 net/core/net_namespace.c:595
 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276
 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
NMI backtrace for cpu 1
CPU: 1 PID: 12912 Comm: kworker/u4:7 Not tainted 5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105
 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x191/0x2f0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x22d/0x390 kernel/rcu/tree_stall.h:342
 print_cpu_stall kernel/rcu/tree_stall.h:625 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:700 [inline]
 rcu_pending kernel/rcu/tree.c:3922 [inline]
 rcu_sched_clock_irq+0x1d0d/0x2a30 kernel/rcu/tree.c:2641
 update_process_times+0x197/0x200 kernel/time/timer.c:1783
 tick_sched_handle kernel/time/tick-sched.c:226 [inline]
 tick_sched_timer+0x27d/0x420 kernel/time/tick-sched.c:1421
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x4cb/0xa60 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:tipc_topsrv_stop net/tipc/topsrv.c:690 [inline]
RIP: 0010:tipc_topsrv_exit_net+0x115/0x310 net/tipc/topsrv.c:715
Code: e8 b0 3e 4c 00 48 89 ef e8 e8 12 00 00 4c 89 ef e8 c0 3c 4c 00 eb 13 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e8 eb 74 f0 f7 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 10 41 83 3f 00
RSP: 0018:ffffc90001a6fb30 EFLAGS: 00000293
RAX: ffffffff898fc3e5 RBX: 1ffff11005a57413 RCX: ffff88808a9ad4c0
RDX: 0000000000000000 RSI: ffffffffadf33fd7 RDI: 000000000000003f
RBP: ffff888029d3e000 R08: ffffffff842b89ea R09: 0000000000000003
R10: fffff5200034df55 R11: 0000000000000004 R12: ffff88802d2ba000
R13: ffff88802d2ba058 R14: 00000000adf33fd7 R15: ffff88802d2ba098
 ops_exit_list net/core/net_namespace.c:175 [inline]
 cleanup_net+0x758/0xc60 net/core/net_namespace.c:595
 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276
 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295