rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9/1:b..l
	(detected by 1, t=10502 jiffies, g=27949, q=72)
task:kworker/u4:0    state:R  running task     stack:21856 pid:    9 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:638
RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627
Code: 2b 00 74 08 4c 89 f7 e8 0c 75 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:ffffc90000ce78c0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff9200019cf24 RCX: 1ffff9200019cec4
RDX: dffffc0000000000 RSI: ffffffff8a8b3da0 RDI: ffffffff8ad904c0
RBP: ffffc90000ce7a20 R08: dffffc0000000000 R09: fffffbfff20e2419
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200019cf20
R13: dffffc0000000000 R14: ffffc90000ce7920 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
 tcp_sk_exit_batch+0x28/0x90 net/ipv4/tcp_ipv4.c:3231
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x763/0xb60 net/core/net_namespace.c:599
 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>
rcu: rcu_preempt kthread starved for 10509 jiffies! g27949 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:26168 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6882 Comm: syz.4.766 Not tainted 5.15.167-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:35 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
RIP: 0010:do_softirq+0xa8/0x240 kernel/softirq.c:454
Code: 00 4c 8d 74 24 40 4c 89 f3 48 c1 eb 03 42 80 3c 23 00 74 08 4c 89 f7 e8 66 a4 7c 00 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 <42> 80 3c 23 00 74 08 4c 89 f7 e8 c9 a3 7c 00 4c 8b 6c 24 40 fa 41
RSP: 0018:ffffc90003447b20 EFLAGS: 00000046
RAX: 0000000080000001 RBX: 1ffff92000688f6c RCX: ffffffff96868f03
RDX: dffffc0000000000 RSI: ffffffff8a8a11c0 RDI: ffffffff8ad904c0
RBP: ffffc90003447bd0 R08: ffffffff8186df90 R09: ffffed100fbd6771
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000688f84 R14: ffffc90003447b60 R15: 1ffff92000688f64
FS:  000055557f91e500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2d4a0d CR3: 00000000674f9000 CR4: 00000000003506f0
DR0: 0000000000002800 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __local_bh_enable_ip+0x1b1/0x1f0 kernel/softirq.c:383
 handle_signal arch/x86/kernel/signal.c:840 [inline]
 arch_do_signal_or_restart+0x1488/0x1890 arch/x86/kernel/signal.c:869
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7795ce0230
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 9a c2 06 00 e8 15 92 f8 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:00007ffd4f0790b8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 00007f7795e6ff80 RCX: 00007f7795cea0e5
RDX: 00007ffd4f0790c0 RSI: 00007ffd4f0791f0 RDI: 0000000000000021
RBP: 00007f7795e71a80 R08: 0000000000000000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000004e656
R13: 00007ffd4f0797f0 R14: 0000000000000226 R15: ffffffffffffffff
 </TASK>