rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=6c54/1/0x4000000000000000 softirq=88399/88400 fqs=2 (detected by 1, t=10502 jiffies, g=123733, q=62 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4427 Comm: udevd Not tainted 6.2.0-rc4-syzkaller-00379-gf883675bf652 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:40 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:75 [inline] RIP: 0010:__raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline] RIP: 0010:_raw_spin_lock_irq+0xa/0x50 kernel/locking/spinlock.c:170 Code: ff 74 24 08 41 b8 01 00 00 00 31 d2 31 f6 e8 dd 5a 5a f7 48 89 ef 58 5d e9 43 bb 5a f7 0f 1f 00 f3 0f 1e fa 55 48 89 fd 9c 58 f6 c4 02 75 30 bf 01 00 00 00 e8 06 38 4d f7 45 31 c9 41 b8 01 RSP: 0018:ffffc90000007e18 EFLAGS: 00000046 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88807d710000 RSI: ffffffff817112ee RDI: ffff8880b982b780 RBP: ffff8880b982b780 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8880b982b880 R14: ffff8880b982b780 R15: ffff88801d682340 FS: 00007f5f02d7d840(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd525d5018 CR3: 00000000266e9000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1689 [inline] __hrtimer_run_queues+0x266/0xfb0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline] __sysvec_apic_timer_interrupt+0x180/0x640 arch/x86/kernel/apic/apic.c:1113 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:handle_mounts fs/namei.c:1529 [inline] RIP: 0010:step_into+0xd8/0x20c0 fs/namei.c:1831 Code: fc ff df 48 89 c1 48 89 85 48 ff ff ff 48 c1 e9 03 4c 89 7d 90 0f b6 14 11 84 d2 74 09 80 fa 03 0f 8e 34 0f 00 00 44 8b 73 38 <31> ff 45 89 f5 41 83 e5 40 44 89 ee e8 a7 d7 9f ff 45 85 ed 0f 84 RSP: 0018:ffffc9000318f8c0 EFLAGS: 00000246 RAX: ffffc9000318fc68 RBX: ffffc9000318fc30 RCX: 1ffff92000631f8d RDX: 0000000000000000 RSI: ffffffff81e1871a RDI: ffffc9000318fc30 RBP: ffffc9000318f9b8 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: ffff88801db99028 R13: dffffc0000000000 R14: 0000000000000013 R15: ffff88813ff16f20 walk_component+0xf5/0x5a0 fs/namei.c:1999 link_path_walk.part.0+0x730/0xdf0 fs/namei.c:2320 link_path_walk fs/namei.c:2245 [inline] path_openat+0x25c/0x2a50 fs/namei.c:3710 do_filp_open+0x1ba/0x410 fs/namei.c:3741 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f5f0292a5a4 Code: f9 41 89 f0 41 83 e2 40 75 2c 89 f0 25 00 00 41 00 3d 00 00 41 00 74 1e 44 89 c2 4c 89 ce bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 2c c3 0f 1f 00 48 8d 44 24 08 c7 44 24 b8 10 RSP: 002b:00007ffee2b633a8 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000561b97bcb140 RCX: 00007f5f0292a5a4 RDX: 0000000000090800 RSI: 0000561b97bb1a80 RDI: 00000000ffffff9c RBP: 0000561b97bde9c0 R08: 0000000000090800 R09: 0000561b97bb1a80 R10: 0000000000000000 R11: 0000000000000287 R12: 0000561b97bb1a80 R13: 00000000000000ff R14: 00007ffee2b63400 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10498 jiffies! g123733 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:28112 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5293 [inline] __schedule+0xb8a/0x5450 kernel/sched/core.c:6606 schedule+0xde/0x1b0 kernel/sched/core.c:6682 schedule_timeout+0x14e/0x2a0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1656 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1855 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted 6.2.0-rc4-syzkaller-00379-gf883675bf652 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x20 kernel/kcov.c:304 Code: 00 00 f3 0f 1e fa 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 8b 0c 24 <89> f2 89 fe bf 05 00 00 00 e9 9a fe ff ff 66 2e 0f 1f 84 00 00 00 RSP: 0018:ffffc90000107970 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff8880b9843ce0 RCX: ffffffff81766463 RDX: ffff88813fe4ba80 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed101730879d R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa287113718 CR3: 000000000c48e000 CR4: 0000000000350ee0 Call Trace: csd_lock_wait kernel/smp.c:413 [inline] smp_call_function_many_cond+0x463/0x10a0 kernel/smp.c:987 on_each_cpu_cond_mask+0x5a/0xa0 kernel/smp.c:1155 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1772 [inline] text_poke_bp_batch+0x22e/0x6b0 arch/x86/kernel/alternative.c:1963 text_poke_flush arch/x86/kernel/alternative.c:2131 [inline] text_poke_flush arch/x86/kernel/alternative.c:2128 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2138 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:799 [inline] toggle_allocation_gate+0xf8/0x230 mm/kfence/core.c:791 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308