rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2657 jiffies s: 1329 root: 0x2/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4476 Comm: syz.4.32 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:__wrmsr arch/x86/include/asm/msr.h:94 [inline] RIP: 0010:native_apic_msr_eoi_write+0x0/0x10 arch/x86/include/asm/apic.h:211 Code: 74 08 4c 89 f7 e8 f0 4b 9b 00 49 8b 06 bf f0 03 00 00 89 de 5b 41 5e 41 5f ff e0 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 0b 08 00 00 31 c0 31 d2 0f 30 c3 0f 1f 40 00 81 ff cf 00 00 00 RSP: 0018:ffffc900001e09b8 EFLAGS: 00000046 RAX: 1ffffffff18c9f66 RBX: ffffffff8c64fb30 RCX: 7ff2d9632412e100 RDX: 1ffffffff1f41208 RSI: 0000000000000000 RDI: 00000000000000b0 RBP: 0000000000000000 R08: ffffffff8fa09048 R09: ffffffff8fa09058 R10: ffffffff8fa09050 R11: ffffffff8fa09043 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007f9a10d2b6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbb02617dac CR3: 0000000058d5e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_eoi arch/x86/include/asm/apic.h:399 [inline] ack_APIC_irq arch/x86/include/asm/apic.h:445 [inline] __sysvec_irq_work+0x53/0x350 arch/x86/kernel/irq_work.c:19 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x4a/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 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 92 31 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900001e0aa0 EFLAGS: 00000206 RAX: 7ff2d9632412e100 RBX: 1ffff9200003c15c RCX: 7ff2d9632412e100 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0d20 RBP: ffffc900001e0b90 R08: ffffffff90af424f R09: 1ffffffff215e849 R10: dffffc0000000000 R11: fffffbfff215e84a R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] ieee80211_iterate_active_interfaces_atomic+0x156/0x170 net/mac80211/util.c:826 mac80211_hwsim_beacon+0xb7/0x1b0 drivers/net/wireless/mac80211_hwsim.c:2147 __run_hrtimer kernel/time/hrtimer.c:1747 [inline] __hrtimer_run_queues+0x560/0xd70 kernel/time/hrtimer.c:1811 hrtimer_run_softirq+0x183/0x2a0 kernel/time/hrtimer.c:1828 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5124 Code: 0f 84 3b 01 00 00 48 85 db 0f 85 5a 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 d0 fd dc 08 e8 eb 2c 2f 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc90004a2f6d8 EFLAGS: 00000286 RAX: 7ff2d9632412e100 RBX: 0000000000000000 RCX: 7ff2d9632412e100 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0d20 RBP: ffffc90004a2f730 R08: ffffffff90af424f R09: 1ffffffff215e849 R10: dffffc0000000000 R11: fffffbfff215e84a R12: ffff8880302b1dc0 R13: dffffc0000000000 R14: ffff888026770000 R15: ffff8880b8f3b5d0 context_switch kernel/sched/core.c:5248 [inline] __schedule+0x11d9/0x40e0 kernel/sched/core.c:6562 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:fib_netdev_event+0x5e/0x470 net/ipv4/fib_frontend.c:1487 Code: 0b f9 49 8b 1f 4c 8d b3 50 06 00 00 e8 4b 29 65 01 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 35 ed 0b f9 4d 8b 36 06 00 00 00 4c 89 e6 e8 55 05 bb f8 49 83 fc 06 75 24 e8 6a 01 RSP: 0018:ffffc90004a2fa50 EFLAGS: 00000246 RAX: 1ffff11004cf0cca RBX: ffff888026786000 RCX: ffff8880302b1dc0 RDX: ffffc9000f4fa000 RSI: 000000000001ad9c RDI: 000000000001ad9d RBP: 0000000000000000 R08: ffffffff90af424f R09: 1ffffffff215e849 R10: dffffc0000000000 R11: fffffbfff215e84a R12: 0000000000000006 R13: dffffc0000000000 R14: ffff888059ca3880 R15: ffffc90004a2fb80 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] unregister_netdevice_many+0x1086/0x1930 net/core/dev.c:11003 unregister_netdevice_queue+0x324/0x370 net/core/dev.c:10934 unregister_netdevice include/linux/netdevice.h:3075 [inline] ppp_release+0xec/0x1f0 drivers/net/ppp/ppp_generic.c:420 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9a0fd9aeb9 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:00007f9a10d2b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffff2 RBX: 00007f9a10016090 RCX: 00007f9a0fd9aeb9 RDX: 000000110c230041 RSI: 00000000c004743e RDI: 0000000000000008 RBP: 00007f9a0fe08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9a10016128 R14: 00007f9a10016090 R15: 00007ffc90354e78