rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (1 GPs behind) idle=a3b/1/0x4000000000000002 softirq=18522/18523 fqs=5247 (detected by 1, t=10502 jiffies, g=26173, q=1203) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6433 Comm: kworker/0:13 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events nsim_dev_trap_report_work 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 a3 8a 7e 65 8b 15 a5 a3 8a 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: 0018:ffffc90000007318 EFLAGS: 00000046 RAX: ffffffff819655e4 RBX: ffffc900000074c0 RCX: ffff88802c03bb80 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000007410 R08: dffffc0000000000 R09: ffffc90000007460 R10: fffff52000000e93 R11: 1ffff92000000e8c R12: dffffc0000000000 R13: ffffc900000074c6 R14: 0000000000000000 R15: ffffc90000007680 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa2c4046f98 CR3: 00000000179f2000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: perf_prepare_sample+0xdb4/0x1cb0 kernel/events/core.c:7732 __perf_event_output kernel/events/core.c:7802 [inline] perf_event_output_forward+0x146/0x280 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+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:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc90000007ae0 EFLAGS: 00000206 RAX: d955461c3fbd7d00 RBX: 1ffff92000000f60 RCX: d955461c3fbd7d00 RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800 RBP: ffffc90000007bb8 R08: dffffc0000000000 R09: fffffbfff1ff5438 R10: fffffbfff1ff5438 R11: 1ffffffff1ff5437 R12: ffffffff8c120c00 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+0x53d/0xc40 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __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 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:___slab_alloc+0xd12/0xdf0 mm/slub.c:3079 Code: 48 c7 44 24 38 00 00 00 00 9c 8f 44 24 38 f7 44 24 38 00 02 00 00 75 40 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 40 75 65 4c 89 e8 48 83 c4 48 5b 41 5c 41 5d 41 5e 41 RSP: 0018:ffffc900021a7a18 EFLAGS: 00000206 RAX: d955461c3fbd7d00 RBX: ffff8880b9043e70 RCX: d955461c3fbd7d00 RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800 RBP: 0000000000000246 R08: dffffc0000000000 R09: fffffbfff1ff5438 R10: fffffbfff1ff5438 R11: 1ffffffff1ff5437 R12: ffff8880b9043e50 R13: ffff888024174000 R14: 0000000000000000 R15: ffff8880b9043e70 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] kmem_cache_alloc_node+0x1c3/0x2d0 mm/slub.c:3261 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:664 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline] nsim_dev_trap_report_work+0x2a1/0xb40 drivers/net/netdevsim/dev.c:762 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287