rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=d4ac/1/0x4000000000000000 softirq=32663/32664 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=31465, q=260 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10231 Comm: syz.4.1993 Not tainted 6.11.0-syzkaller-11993-g3efc57369a0c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 84 9c 9b 0c 48 89 de 5b e9 d3 a6 5a 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 80 d7 03 00 65 8b 15 a0 f1 RSP: 0018:ffffc90000a18d20 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000010003 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff9a5882cb R09: 1ffffffff34b1059 R10: dffffc0000000000 R11: fffffbfff34b105a R12: dffffc0000000000 R13: ffff8880b872c980 R14: ffff88807574b340 R15: ffff8880b872c880 FS: 0000555595179500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3201dff8 CR3: 000000002843c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] static_key_false include/linux/jump_label.h:207 [inline] trace_hrtimer_start include/trace/events/timer.h:222 [inline] debug_activate kernel/time/hrtimer.c:479 [inline] enqueue_hrtimer+0x3a/0x3c0 kernel/time/hrtimer.c:1085 __run_hrtimer kernel/time/hrtimer.c:1708 [inline] __hrtimer_run_queues+0x6cb/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1026 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1043 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 3e 17 35 f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 43 d5 9c f5 65 8b 05 44 79 3d 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc90003c47c20 EFLAGS: 00000206 RAX: 6b63105e6a799600 RBX: 1ffff92000788f88 RCX: ffffffff9a396903 RDX: dffffc0000000000 RSI: ffffffff8c0acac0 RDI: 0000000000000001 RBP: ffffc90003c47cb8 R08: ffffffff901bb7af R09: 1ffffffff20376f5 R10: dffffc0000000000 R11: fffffbfff20376f6 R12: dffffc0000000000 R13: 1ffff92000788f84 R14: ffffc90003c47c40 R15: 0000000000000246 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] alarm_try_to_cancel+0x131/0x3c0 kernel/time/alarmtimer.c:425 alarm_cancel+0x16/0x60 kernel/time/alarmtimer.c:442 timerfd_release+0x1b1/0x250 fs/timerfd.c:242 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f187c97dff9 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:00007fffd085f228 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000002ea52 RCX: 00007f187c97dff9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f187cb37a80 R08: 0000000000000001 R09: 00007fffd085f51f R10: 00007f187c800000 R11: 0000000000000246 R12: 000000000002ea9c R13: 00007fffd085f330 R14: 0000000000000032 R15: ffffffffffffffff rcu: rcu_preempt kthread starved for 10502 jiffies! g31465 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:25136 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 10234 Comm: syz.1.1995 Not tainted 6.11.0-syzkaller-11993-g3efc57369a0c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f3/0x2ca0 kernel/smp.c:884 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 46 f9 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 f1 f4 0b 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 d5 f4 RSP: 0018:ffffc9000312f960 EFLAGS: 00000246 RAX: ffffffff8188f0fb RBX: 1ffff110170e8911 RCX: 0000000000040000 RDX: ffffc9000a7c0000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc9000312fb60 R08: ffffffff8188f0ca R09: 1ffffffff2847ef8 R10: dffffc0000000000 R11: fffffbfff2847ef9 R12: dffffc0000000000 R13: ffff8880b8744888 R14: ffff8880b863fc40 R15: 0000000000000001 FS: 00007ff91cc296c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff91cc28f98 CR3: 000000002993e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2085 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2295 text_poke_flush arch/x86/kernel/alternative.c:2486 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2493 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_slow_inc_cpuslocked+0x80/0xf0 kernel/jump_label.c:168 static_key_slow_inc+0x1a/0x30 kernel/jump_label.c:191 bpf_enable_runtime_stats kernel/bpf/syscall.c:5465 [inline] bpf_enable_stats+0xfe/0x140 kernel/bpf/syscall.c:5484 __sys_bpf+0x75b/0x810 kernel/bpf/syscall.c:5717 __do_sys_bpf kernel/bpf/syscall.c:5741 [inline] __se_sys_bpf kernel/bpf/syscall.c:5739 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5739 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff91bd7dff9 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:00007ff91cc29038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007ff91bf35f80 RCX: 00007ff91bd7dff9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000020 RBP: 00007ff91bdf0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007ff91bf35f80 R15: 00007ffd8effd268