rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2691 jiffies s: 265917 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: 9918 Comm: syz.4.10184 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x23/0x80 kernel/kcov.c:313 Code: 48 89 44 11 20 c3 90 48 8b 04 24 65 48 8b 15 b4 f6 7f 7e 65 8b 0d b5 f6 7f 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b <83> ba 1c 16 00 00 00 74 52 8b 8a f8 15 00 00 83 f9 03 75 47 48 8b RSP: 0018:ffffc900001e0878 EFLAGS: 00000046 RAX: ffffffff818a8ca6 RBX: 0000000000000014 RCX: 0000000000000100 RDX: ffff888044d19dc0 RSI: 0000000000000001 RDI: 0000000000000008 RBP: 0000000000000001 R08: ffffffff8e1fcd2f R09: 1ffffffff1c3f9a5 R10: dffffc0000000000 R11: fffffbfff1c3f9a6 R12: 0000000000000001 R13: 0000000000000001 R14: ffffc900001e0900 R15: 00000000000000a8 FS: 00007fdd97ca66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6cb4f456b8 CR3: 000000006779c000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: perf_trace_buf_alloc+0xc6/0x300 kernel/trace/trace_event_perf.c:419 perf_trace_preemptirq_template+0x143/0x320 include/trace/events/preemptirq.h:14 trace_irq_disable include/trace/events/preemptirq.h:36 [inline] trace_hardirqs_off_finish+0x13f/0x180 kernel/trace/trace_preemptirq.c:67 irqentry_enter+0x33/0x50 kernel/entry/common.c:382 sysvec_irq_work+0xa/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: 0ea7ecb1164bdd00 RBX: 1ffff9200003c15c RCX: 0ea7ecb1164bdd00 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0de0 RBP: ffffc900001e0b90 R08: ffffffff90af524f R09: 1ffffffff215ea49 R10: dffffc0000000000 R11: fffffbfff215ea4a 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:__raw_callee_save___kvm_vcpu_is_preempted+0xf/0x20 Code: be 03 00 00 00 e8 11 c5 00 03 bf 21 10 01 c0 be 0e 00 00 00 e9 02 c5 00 03 00 00 48 8b 04 fd 80 f9 64 8c 80 b8 50 74 02 00 00 <0f> 95 c0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 48 89 e5 41 RSP: 0018:ffffc90003b2f800 EFLAGS: 00000246 RAX: ffff8880b8e00000 RBX: 0000000000000000 RCX: ffffffff8163a0db RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000 RBP: 1ffffffff1ba8c78 R08: ffffffff8dd463c7 R09: 1ffffffff1ba8c78 R10: dffffc0000000000 R11: fffffbfff1ba8c79 R12: ffffffff8dd463c0 R13: ffffffff8dd46410 R14: dffffc0000000000 R15: ffff888081b68000 pv_vcpu_is_preempted arch/x86/include/asm/paravirt.h:613 [inline] vcpu_is_preempted arch/x86/include/asm/qspinlock.h:63 [inline] owner_on_cpu include/linux/sched.h:2291 [inline] mutex_spin_on_owner+0x196/0x350 kernel/locking/mutex.c:373 mutex_optimistic_spin kernel/locking/mutex.c:476 [inline] __mutex_lock_common kernel/locking/mutex.c:607 [inline] __mutex_lock+0x187/0xaf0 kernel/locking/mutex.c:747 ipv6_route_ioctl+0x31e/0x500 net/ipv6/route.c:4511 inet6_ioctl+0x207/0x280 net/ipv6/af_inet6.c:586 sock_do_ioctl+0xfb/0x320 net/socket.c:1201 sock_ioctl+0x4d2/0x710 net/socket.c:1320 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fdd96d9c799 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:00007fdd97ca6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fdd97015fa0 RCX: 00007fdd96d9c799 RDX: 0000200000000000 RSI: 000000000000890b RDI: 000000000000000e RBP: 00007fdd96e32bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdd97016038 R14: 00007fdd97015fa0 R15: 00007fffafd627c8