rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=fd5c/1/0x4000000000000000 softirq=49139/49140 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=35177, q=114 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11666 Comm: syz.5.1267 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__lock_acquire+0xcb/0xd20 kernel/locking/lockdep.c:-1 Code: 84 02 0c 00 00 8b 0d 04 cb 0e 18 8b 97 e8 0a 00 00 85 c9 0f 94 c1 83 fa 30 40 0f 93 c6 40 20 ce 40 80 fe 01 0f 84 30 01 00 00 <44> 89 74 24 1c 89 6c 24 10 44 8b b4 24 88 00 00 00 8b 6c 24 78 41 RSP: 0000:ffffc9000e8af690 EFLAGS: 00000097 RAX: ffffffff934a0b58 RBX: ffff8880b8727a98 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888026c33c00 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000001 R10: dffffc0000000000 R11: ffffed10170e4f51 R12: 0000000000000000 R13: ffff8880b8727a98 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f333a7de6c0(0000) GS:ffff888125d11000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c309eb4 CR3: 000000007e58a000 CR4: 00000000003526f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:171 [inline] hrtimer_try_to_cancel+0x22b/0x420 kernel/time/hrtimer.c:1362 hrtimer_cancel+0x3b/0x50 kernel/time/hrtimer.c:1488 perf_swevent_cancel_hrtimer kernel/events/core.c:11817 [inline] cpu_clock_event_stop+0xd9/0x130 kernel/events/core.c:11867 __perf_event_overflow+0x580/0xe40 kernel/events/core.c:10333 perf_swevent_hrtimer+0x3c5/0x550 kernel/events/core.c:11773 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x4dd/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7f333998eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f333a7de038 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f3339be5fa0 RCX: 00007f333998eec9 RDX: 0000000000000006 RSI: 0000000000002402 RDI: 0000000000000003 RBP: 00007f3339a11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3339be6038 R14: 00007f3339be5fa0 R15: 00007ffd2e3d0e48 rcu: rcu_preempt kthread starved for 10502 jiffies! g35177 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 11663 Comm: syz.9.1268 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 45 5f RSP: 0018:ffffc9000eb1f580 EFLAGS: 00000293 RAX: ffffffff81b4665b RBX: 1ffff110170e7f61 RCX: ffff88802d843c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000eb1f700 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6 R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: ffff8880b873fb08 R13: dffffc0000000000 R14: ffff8880b863b1c0 R15: 0000000000000001 FS: 00007fbdc647f6c0(0000) GS:ffff888125c11000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000001dec0000 CR4: 00000000003526f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2653 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863 __static_call_transform+0x4eb/0x750 arch/x86/kernel/static_call.c:111 arch_static_call_transform+0x98/0xc0 arch/x86/kernel/static_call.c:-1 __static_call_update+0xe4/0x5d0 kernel/static_call_inline.c:147 tracepoint_update_call kernel/tracepoint.c:271 [inline] tracepoint_add_func+0x91e/0xa10 kernel/tracepoint.c:312 tracepoint_probe_register_prio_may_exist+0x5f/0xa0 kernel/tracepoint.c:435 bpf_raw_tp_link_attach+0x4f0/0x6c0 kernel/bpf/syscall.c:4235 bpf_raw_tracepoint_open+0x1b2/0x220 kernel/bpf/syscall.c:4266 __sys_bpf+0x73e/0x860 kernel/bpf/syscall.c:6176 __do_sys_bpf kernel/bpf/syscall.c:6244 [inline] __se_sys_bpf kernel/bpf/syscall.c:6242 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6242 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbdc558eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbdc647f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fbdc57e5fa0 RCX: 00007fbdc558eec9 RDX: 0000000000000010 RSI: 0000200000000200 RDI: 0000000000000011 RBP: 00007fbdc5611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbdc57e6038 R14: 00007fbdc57e5fa0 R15: 00007fffbb71b588