rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5343/1:b..l P4394/1:b..l
	(detected by 0, t=10502 jiffies, g=19057, q=45)
task:kworker/u4:13   state:R  running task     stack:23416 pid: 4394 ppid:     2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627
Code: 2b 00 74 08 4c 89 f7 e8 9c 9e 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc9000327f8c0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff9200064ff24 RCX: 1ffff9200064fec4
RDX: dffffc0000000000 RSI: ffffffff8aab3e20 RDI: ffffffff8af9f2c0
RBP: ffffc9000327fa20 R08: dffffc0000000000 R09: fffffbfff2131821
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200064ff20
R13: dffffc0000000000 R14: ffffc9000327f920 R15: 0000000000000246
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 inet_twsk_purge+0x129/0x9d0 net/ipv4/inet_timewait_sock.c:268
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x886/0xc90 net/core/net_namespace.c:618
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
task:syz-executor    state:R  running task     stack:20568 pid: 5343 ppid:  5331 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x77/0x290 mm/kasan/generic.c:189
Code: 03 49 bb 01 00 00 00 00 fc ff df 4f 8d 34 1a 4c 89 f5 4c 29 cd 48 83 fd 10 7f 26 48 85 ed 0f 84 3a 01 00 00 49 f7 d2 49 01 da <41> 80 39 00 0f 85 c4 01 00 00 49 ff c1 49 ff c2 75 ee e9 1d 01 00
RSP: 0018:ffffc9000344fa50 EFLAGS: 00000286
RAX: ffffffff81d9aa01 RBX: 1ffff92000689f78 RCX: ffffffff81d9aa56
RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc9000344fbc0
RBP: 0000000000000002 R08: dffffc0000000000 R09: fffff52000689f79
R10: ffffffffffffffff R11: dffffc0000000001 R12: 0000000000000010
R13: ffffc9000344fbc0 R14: fffff52000689f7a R15: ffffc9000344fbc0
 memcpy+0x3c/0x60 mm/kasan/shadow.c:66
 path_init+0x8a6/0x1190 fs/namei.c:2379
 path_parentat fs/namei.c:2501 [inline]
 __filename_parentat+0x241/0x6c0 fs/namei.c:2526
 filename_parentat fs/namei.c:2544 [inline]
 filename_create+0xf2/0x530 fs/namei.c:3816
 do_mkdirat+0xb3/0x520 fs/namei.c:4080
 __do_sys_mkdirat fs/namei.c:4105 [inline]
 __se_sys_mkdirat fs/namei.c:4103 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4103
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f36e77f99d7
RSP: 002b:00007ffd6ace2358 EFLAGS: 00000202 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ffd6ace23b0 RCX: 00007f36e77f99d7
RDX: 00000000000001ff RSI: 00007ffd6ace23b0 RDI: 00000000ffffff9c
RBP: 00007ffd6ace239c R08: 0000000000000004 R09: 00007ffd6ace20f6
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000020
R13: 00000000000927c0 R14: 000000000003edbe R15: 00007ffd6ace23f0
 </TASK>
rcu: rcu_preempt kthread starved for 10557 jiffies! g19057 f0x0 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:26240 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562