rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=165545, q=66)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295059736-4295049234), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g165545 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:28696 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4955 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6236
 schedule+0xd3/0x270 kernel/sched/core.c:6315
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1966
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2139
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 29519 Comm: kworker/u4:1 Not tainted 5.15.0-rc3-next-20211001-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+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:458
 print_other_cpu_stall kernel/rcu/tree_stall.h:563 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:706 [inline]
 rcu_pending kernel/rcu/tree.c:3889 [inline]
 rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2608
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x70 kernel/kcov.c:286
Code: b7 c9 48 83 c2 01 48 c7 44 30 e0 03 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 5b c3 0f 1f 80 00 00 00 00 <41> 89 f8 bf 03 00 00 00 4c 8b 14 24 89 f1 65 48 8b 34 25 40 70 02
RSP: 0018:ffffc90004817be0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 000000007c31dac0 RCX: 0000000000000000
RDX: ffff8880289dd700 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88807c1de800 R08: 000000007c31dabf R09: 0000000000000000
R10: ffffffff83f2a41c R11: 0000000000000000 R12: ffff88807c1de858
R13: ffffed100f83bd13 R14: ffff88803cf91800 R15: 0000000000000001
 tipc_topsrv_stop net/tipc/topsrv.c:690 [inline]
 tipc_topsrv_exit_net+0x259/0x5d0 net/tipc/topsrv.c:715
 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:168
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2297
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
----------------
Code disassembly (best guess):
   0:	b7 c9                	mov    $0xc9,%bh
   2:	48 83 c2 01          	add    $0x1,%rdx
   6:	48 c7 44 30 e0 03 00 	movq   $0x3,-0x20(%rax,%rsi,1)
   d:	00 00
   f:	48 89 7c 30 e8       	mov    %rdi,-0x18(%rax,%rsi,1)
  14:	48 89 4c 30 f0       	mov    %rcx,-0x10(%rax,%rsi,1)
  19:	4c 89 54 d8 20       	mov    %r10,0x20(%rax,%rbx,8)
  1e:	48 89 10             	mov    %rdx,(%rax)
  21:	5b                   	pop    %rbx
  22:	c3                   	retq
  23:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
* 2a:	41 89 f8             	mov    %edi,%r8d <-- trapping instruction
  2d:	bf 03 00 00 00       	mov    $0x3,%edi
  32:	4c 8b 14 24          	mov    (%rsp),%r10
  36:	89 f1                	mov    %esi,%ecx
  38:	65                   	gs
  39:	48                   	rex.W
  3a:	8b                   	.byte 0x8b
  3b:	34 25                	xor    $0x25,%al
  3d:	40 70 02             	rex jo 0x42