rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=90d/1/0x4000000000000000 softirq=21469/21470 fqs=4050 (t=10500 jiffies g=28417 q=1246) NMI backtrace for cpu 0 CPU: 0 PID: 9919 Comm: syz.1.1638 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x6ea/0x1120 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4ad/0xb70 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:ffs arch/x86/include/asm/bitops.h:297 [inline] RIP: 0010:handle_softirqs+0x1a9/0x830 kernel/softirq.c:564 Code: 24 78 44 89 64 24 28 0f b7 db 48 c7 c7 00 04 2a 8a e8 cb 07 71 08 65 66 c7 05 41 66 ba 7e 00 00 e8 2c 09 36 00 fb 89 5c 24 34 ff ff ff ff 0f bc 44 24 34 41 89 c5 41 ff c5 0f 85 d2 00 00 00 RSP: 0018:ffffc90000007e20 EFLAGS: 00000282 RAX: 1a72602b7b13b500 RBX: 0000000000000200 RCX: 1a72602b7b13b500 RDX: dffffc0000000000 RSI: ffffffff8a2b1c00 RDI: ffffffff8a79e740 RBP: ffffc90000007f30 R08: ffffffff901b70cf R09: 1ffffffff2036e19 R10: dffffc0000000000 R11: fffffbfff2036e1a R12: 000000000000000a R13: 0000000000000000 R14: ffff88805d7e3b80 R15: dffffc0000000000 __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 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:rcu_read_unlock_special+0x0/0x4a0 kernel/rcu/tree_plugin.h:625 Code: 36 a4 58 00 eb b0 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 94 49 89 fd 4c 89 f7 e8 1c a4 58 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:ffffc90003277728 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff88805d7e3fbc RCX: 0000000000080000 RDX: ffffc90003de3000 RSI: 000000000007ffff RDI: ffff88805d7e3b80 RBP: ffffc90003277870 R08: dffffc0000000000 R09: 1ffffffff2036e18 R10: dffffc0000000000 R11: fffffbfff2036e19 R12: 1ffff1100bafc7f7 R13: dffffc0000000000 R14: ffff88805d7e3fc0 R15: dffffc0000000000 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] inet_twsk_purge+0x7a2/0x840 net/ipv4/inet_timewait_sock.c:309 ops_exit_list net/core/net_namespace.c:177 [inline] setup_net+0x844/0xa10 net/core/net_namespace.c:365 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+0x1834/0x3e20 kernel/fork.c:2293 kernel_clone+0x23f/0x990 kernel/fork.c:2679 __do_sys_clone kernel/fork.c:2796 [inline] __se_sys_clone kernel/fork.c:2780 [inline] __x64_sys_clone+0x19a/0x210 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: 0033:0x7f652cb32cb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f652ad8dfd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f652cdadfa0 RCX: 00007f652cb32cb9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000010eb22f000 RBP: 00007f652cba0bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f652cdae038 R14: 00007f652cdadfa0 R15: 00007fff60a147a8