rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (1 GPs behind) idle=a35/1/0x4000000000000002 softirq=22698/22699 fqs=2099 (detected by 1, t=10505 jiffies, g=26297, q=685) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9600 Comm: syz.1.1391 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2a/0x60 kernel/kcov.c:206 Code: 48 8b 04 24 65 48 8b 0d a4 39 89 7e 65 8b 15 a5 39 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 <74> 2c 8b 91 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b RSP: 0000:ffffc90000007308 EFLAGS: 00000046 RAX: ffffffff8197bfee RBX: 0000000000000000 RCX: ffff888023e83b80 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffc900000074d7 R09: ffffc900000074a0 R10: dffffc0000000000 R11: fffff52000000e9b R12: ffff88806214c8fa R13: ffffc900000076c0 R14: ffff88806214c7a0 R15: ffffc90000007506 FS: 00007f478ee2d6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faf9a2feff0 CR3: 00000000245ae000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0100000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __perf_event_header__init_id+0x36e/0x500 kernel/events/core.c:7112 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 d2 df 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: 0000:ffffc90000007b00 EFLAGS: 00000206 RAX: 98cc9793c6ac1000 RBX: 1ffff92000000f64 RCX: 98cc9793c6ac1000 RDX: dffffc0000000000 RSI: ffffffff8a2b3100 RDI: ffffffff8a7a0700 RBP: ffffc90000007bd8 R08: ffffffff901d60cf R09: 1ffffffff203ac19 R10: dffffc0000000000 R11: fffffbfff203ac1a 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] ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4f2/0xb70 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766 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 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804 Code: be ff ff ff ff e8 dc 60 68 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 86 cc 71 08 e8 81 e6 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c RSP: 0000:ffffc900037dede8 EFLAGS: 00000286 RAX: 98cc9793c6ac1000 RBX: ffff8880b903a340 RCX: 98cc9793c6ac1000 RDX: dffffc0000000000 RSI: ffffffff8a2b3100 RDI: ffffffff8a7a0700 RBP: 1ffff11017207613 R08: ffffffff901d60cf R09: 1ffffffff203ac19 R10: dffffc0000000000 R11: fffffbfff203ac1a R12: 1ffff110172075c1 R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000 finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921 context_switch kernel/sched/core.c:5052 [inline] __schedule+0x11f7/0x43c0 kernel/sched/core.c:6395 preempt_schedule_notrace+0xd9/0x120 kernel/sched/core.c:6650 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0xb5/0x8a0 kernel/locking/lockdep.c:5634 up_write+0x29/0x420 kernel/locking/rwsem.c:1603 kernfs_add_one+0x4c9/0x6c0 fs/kernfs/dir.c:778 __kernfs_create_file+0x233/0x2e0 fs/kernfs/file.c:1014 sysfs_add_file_mode_ns+0x2d4/0x3a0 fs/sysfs/file.c:317 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x495/0xd00 fs/sysfs/group.c:149 internal_create_groups fs/sysfs/group.c:189 [inline] sysfs_create_groups+0x55/0x120 fs/sysfs/group.c:215 device_add_groups drivers/base/core.c:2491 [inline] device_add_attrs+0x137/0x6a0 drivers/base/core.c:2650 device_add+0x64b/0xfb0 drivers/base/core.c:3363 netdev_register_kobject+0x184/0x320 net/core/net-sysfs.c:2014 register_netdevice+0x1042/0x1710 net/core/dev.c:10423 register_netdev+0x37/0x50 net/core/dev.c:10547 loopback_net_init+0x71/0x140 drivers/net/loopback.c:216 ops_init+0x357/0x600 net/core/net_namespace.c:138 setup_net+0x39e/0xa10 net/core/net_namespace.c:333 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: 0033:0x7f4790bd3e59 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:00007f478ee2cfd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f4790e4cfa0 RCX: 00007f4790bd3e59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000061000600 RBP: 00007f4790c69d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f4790e4d038 R14: 00007f4790e4cfa0 R15: 00007fff8cb8f878