rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (1 GPs behind) idle=941/1/0x4000000000000002 softirq=63296/63297 fqs=5250 
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P21989
	(detected by 1, t=10502 jiffies, g=92605, q=560)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 21989 Comm: syz.5.4727 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__rcu_read_lock+0x2d/0x50 kernel/rcu/tree_plugin.h:400
Code: 8b 1d 77 13 9e 7e 48 81 c3 3c 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 11 ff 03 8b 03 <3d> 00 00 00 40 7d 02 5b c3 0f 0b eb fa 89 d9 80 e1 07 80 c1 03 38
RSP: 0018:ffffc900000077b0 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffff88802bbf843c RCX: dffffc0000000000
RDX: 0000000000000100 RSI: ffffc900000079c0 RDI: ffff88801999b5b8
RBP: ffffc900000078d0 R08: dffffc0000000000 R09: ffffed1003333746
R10: ffffed1003333746 R11: 1ffff11003333745 R12: dffffc0000000000
R13: 1ffff92000000efc R14: ffffc90000007860 R15: ffffc900000079c0
FS:  00007f0f493c26c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557ccb5808 CR3: 000000007d39f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 rcu_read_lock include/linux/rcupdate.h:738 [inline]
 __perf_event_output kernel/events/core.c:7800 [inline]
 perf_event_output_forward+0x92/0x280 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2be/0x380 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:ffs arch/x86/include/asm/bitops.h:297 [inline]
RIP: 0010:handle_softirqs+0x1a9/0x820 kernel/softirq.c:564
Code: 24 78 44 89 64 24 28 0f b7 db 48 c7 c7 80 04 0a 8a e8 5b 07 61 08 65 66 c7 05 51 21 bb 7e 00 00 e8 3c 72 35 00 fb 89 5c 24 34 <b8> ff ff ff ff 0f bc 44 24 34 41 89 c5 41 ff c5 0f 85 c1 00 00 00
RSP: 0018:ffffc90000007e20 EFLAGS: 00000282
RAX: db6827c5ea6f9f00 RBX: 0000000000000200 RCX: db6827c5ea6f9f00
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90000007f30 R08: dffffc0000000000 R09: fffffbfff1ff7c1a
R10: fffffbfff1ff7c1a R11: 1ffffffff1ff7c19 R12: 000000000000000a
R13: 0000000000000000 R14: ffff88802bbf8000 R15: dffffc0000000000
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 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:rcu_read_unlock_special+0x0/0x480 kernel/rcu/tree_plugin.h:625
Code: e6 d6 57 00 eb b0 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 94 49 89 fd 4c 89 f7 e8 cc d6 57 00 4c 89 ef eb 84 0f 1f 80 00 00 00 00 <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec a0 00
RSP: 0018:ffffc90002eef800 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff88802bbf843c RCX: 0000000000080000
RDX: ffffc9000ef6b000 RSI: 000000000007ffff RDI: ffff88802bbf8000
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1ff7c19
R10: fffffbfff1ff7c19 R11: 1ffffffff1ff7c18 R12: 1ffff1100577f087
R13: dffffc0000000000 R14: ffff88802bbf8440 R15: dffffc0000000000
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 net_generic include/net/netns/generic.h:47 [inline]
 ops_free_list+0x271/0x330 net/core/net_namespace.c:186
 setup_net+0x895/0x9f0 net/core/net_namespace.c:369
 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503
 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
 copy_namespaces+0x37d/0x3e0 kernel/nsproxy.c:178
 copy_process+0x180f/0x3e00 kernel/fork.c:2293
 kernel_clone+0x219/0x930 kernel/fork.c:2679
 __do_sys_clone kernel/fork.c:2796 [inline]
 __se_sys_clone kernel/fork.c:2780 [inline]
 __x64_sys_clone+0x170/0x1c0 kernel/fork.c:2780
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0f4b17bfc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0f493c1fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f0f4b3d3090 RCX: 00007f0f4b17bfc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f0f4b1fef91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f0f4b3d3128 R14: 00007f0f4b3d3090 R15: 00007ffdcc766a88
 </TASK>
task:syz.5.4727      state:R  running task     stack:21536 pid:21989 ppid: 20575 flags:0x0000400e
Call Trace:
 <TASK>
 </TASK>