rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P144/1:b..l
	(detected by 0, t=10502 jiffies, g=29505, q=25374)
task:kworker/u4:1    state:R  running task     stack:22640 pid:  144 ppid:     2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:205
Code: 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 20 bc 10 0c 48 89 de 5b e9 37 42 44 00 00 00 cc cc 00 00 cc 48 8b 04 24 <65> 48 8b 0d 74 4d 89 7e 65 8b 15 75 4d 89 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc9000173fa38 EFLAGS: 00000202
RAX: ffffffff8863767b RBX: 0000000000000001 RCX: fb819d5c8fe47400
RDX: 0000000000000000 RSI: ffffffff8a79f7e0 RDI: ffffffff8a79f7a0
RBP: ffffc9000173fb50 R08: dffffc0000000000 R09: 1ffffffff203a618
R10: dffffc0000000000 R11: fffffbfff203a619 R12: 000000000005c3ff
R13: dffffc0000000000 R14: ffff88802cae2000 R15: ffffffff8d617440
 rcu_read_lock include/linux/rcupdate.h:741 [inline]
 inet_twsk_purge+0x13b/0x840 net/ipv4/inet_timewait_sock.c:268
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x791/0xba0 net/core/net_namespace.c:635
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread starved for 10474 jiffies! g29505 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:28016 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 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
CPU: 1 PID: 8932 Comm: syz.6.1153 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lockdep_hardirqs_off+0x48/0x100 kernel/locking/lockdep.c:4370
Code: 90 00 00 00 48 89 fb 65 8b 05 6c 45 46 76 a9 00 00 f0 00 74 68 83 3d 16 75 71 0c 00 75 15 48 c7 04 24 00 00 00 00 9c 8f 04 24 <f7> 04 24 00 02 00 00 75 79 65 8b 05 e8 4b 46 76 85 c0 74 56 65 4c
RSP: 0018:ffffc9000316fbe0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff81493d07 RCX: d83bb59bd2417400
RDX: ffffc90012c86000 RSI: ffffffff8a2b27a0 RDI: ffffffff8a79f800
RBP: ffffc9000316fcb0 R08: ffff88802828bb87 R09: 1ffff11005051770
R10: dffffc0000000000 R11: ffffed1005051771 R12: ffffffff812c28e5
R13: 1ffff9200062dfff R14: dffffc0000000000 R15: 1ffff9200062df84
FS:  00007f8600c596c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8600c7a6a8 CR3: 000000004f59f000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 trace_hardirqs_off+0x14/0x70 kernel/trace/trace_preemptirq.c:76
 __local_bh_enable_ip+0xd7/0x1c0 kernel/softirq.c:383
 handle_signal arch/x86/kernel/signal.c:840 [inline]
 arch_do_signal_or_restart+0xec1/0x12c0 arch/x86/kernel/signal.c:869
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8602a3fbd0
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d a2 22 07 00 e8 a5 65 f9 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:00007f8600c58b38 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f8602c9a098 RCX: 00007f8602a20629
RDX: 00007f8600c58b40 RSI: 00007f8600c58c70 RDI: 0000000000000021
RBP: 00007f8602c9a090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8602c9a128 R14: 00007ffd26177860 R15: 00007ffd26177948
 </TASK>