rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (1 ticks this GP) idle=20b/1/0x4000000000000002 softirq=38557/38561 fqs=2100 
	(detected by 1, t=10503 jiffies, g=54177, q=1371)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9321 Comm: kworker/u4:11 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: netns cleanup_net
RIP: 0010:__perf_event_header__init_id+0xb3/0x500 kernel/events/core.c:7103
Code: 49 83 c7 06 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 c3 03 00 00 66 41 01 2f 48 89 de 48 83 e6 02 31 ff e8 7d 7b e1 ff <48> 89 d8 48 83 e0 02 4c 8b 2c 24 75 0a e8 8b 77 e1 ff e9 ae 01 00
RSP: 0018:ffffc90000006fd0 EFLAGS: 00000046
RAX: ffffffff8197d153 RBX: 0000000000000000 RCX: ffff88802a591dc0
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc90000007197 R09: ffffc90000007160
R10: dffffc0000000000 R11: fffff52000000e33 R12: ffff8880505f9342
R13: dffffc0000000000 R14: ffff8880505f91e8 R15: ffffc900000071c6
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd433af06b8 CR3: 00000000468f1000 CR4: 00000000003506f0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 perf_prepare_sample+0x158/0x1cd0 kernel/events/core.c:7624
 __perf_event_output kernel/events/core.c:7802 [inline]
 perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_swevent_overflow kernel/events/core.c:9591 [inline]
 perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629
 perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 f2 cc 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900000077c0 EFLAGS: 00000206
RAX: 33e13478a44f0b00 RBX: 1ffff92000000efc RCX: 33e13478a44f0b00
RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: ffffffff8a7a09c0
RBP: ffffc900000078a0 R08: ffffffff901d81bf R09: 1ffffffff203b037
R10: dffffc0000000000 R11: fffffbfff203b038 R12: ffffffff8c323800
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 ndisc_send_skb+0xde0/0x1500 net/ipv6/ndisc.c:521
 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3956
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x53e/0x800 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:408
Code: 8a e8 b6 2b 74 08 65 66 8b 05 5e 39 ba 7e 66 85 c0 75 54 bf 01 00 00 00 e8 ef 26 09 00 e8 9a 15 36 00 fb 65 8b 05 0a 10 b9 7e <85> c0 75 05 e8 59 1d b7 ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc9000358fa20 EFLAGS: 00000282
RAX: 0000000080000000 RBX: 0000000000000200 RCX: 33e13478a44f0b00
RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: ffffffff8a7a09c0
RBP: ffffc9000358fab8 R08: ffffffff901d8157 R09: 1ffffffff203b02a
R10: dffffc0000000000 R11: fffffbfff203b02b R12: ffffffff8824bbb5
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920006b1f44
 get_next_corpse net/netfilter/nf_conntrack_core.c:2360 [inline]
 nf_ct_iterate_cleanup+0x347/0x3c0 net/netfilter/nf_conntrack_core.c:2381
 nf_conntrack_cleanup_net_list+0x6f/0x1f0 net/netfilter/nf_conntrack_core.c:2570
 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>