rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=c90c/1/0x4000000000000000 softirq=34841/34842 fqs=45 rcu: (detected by 1, t=10502 jiffies, g=29765, q=1080 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8809 Comm: udevd Not tainted 6.13.0-rc2-syzkaller-00031-gf92f4749861b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:147 [inline] RIP: 0010:lock_release+0x3c6/0x6f0 kernel/locking/lockdep.c:5873 Code: 19 0f 84 87 01 00 00 48 c7 c7 60 db 6c 8b e8 31 42 b2 09 b8 ff ff ff ff 65 0f c1 05 cc de 8b 7e 83 f8 01 0f 85 fe 01 00 00 9c <58> f6 c4 02 0f 85 e9 01 00 00 48 f7 04 24 00 02 00 00 74 01 fb 48 RSP: 0018:ffffc90000007c18 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff92000000f86 RCX: ffffc90000007c70 RDX: 1ffff1100b3aea6a RSI: ffffffff8b6cdb60 RDI: ffffffff8bd1d280 RBP: d57e1d102ea6ccdd R08: 0000000000000000 R09: fffffbfff20be2ba R10: ffffffff905f15d7 R11: 0000000000000002 R12: 0000000000000002 R13: 0000000000000003 R14: ffff888059d75358 R15: ffff888059d74880 FS: 00007f17d9f74280(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3459f63ce0 CR3: 0000000079040000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:194 debug_object_activate+0x2e6/0x4a0 lib/debugobjects.c:836 debug_hrtimer_activate kernel/time/hrtimer.c:428 [inline] debug_activate kernel/time/hrtimer.c:469 [inline] enqueue_hrtimer+0x25/0x3c0 kernel/time/hrtimer.c:1076 __run_hrtimer kernel/time/hrtimer.c:1756 [inline] __hrtimer_run_queues+0x903/0xae0 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 7e 60 e8 a3 ff ff ff 31 c0 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 48 8b 15 74 d5 69 7e 65 8b 05 75 d5 69 7e a9 00 01 RSP: 0018:ffffc90003e8fb50 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc90003e8fc60 RCX: ffffffff821203a3 RDX: 1ffff920007d1f90 RSI: ffffffff821203b1 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffc90003e8fc98 R13: ffffc90003e8fca0 R14: ffff88807f357318 R15: ffffc90003e8fc60 leave_rcu fs/namei.c:741 [inline] try_to_unlazy+0x197/0x660 fs/namei.c:851 complete_walk+0x10b/0x330 fs/namei.c:956 path_parentat+0xe5/0x1b0 fs/namei.c:2683 __filename_parentat+0x22d/0x680 fs/namei.c:2705 filename_parentat fs/namei.c:2723 [inline] do_unlinkat+0x106/0x760 fs/namei.c:4562 __do_sys_unlink fs/namei.c:4635 [inline] __se_sys_unlink fs/namei.c:4633 [inline] __x64_sys_unlink+0xc5/0x110 fs/namei.c:4633 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f17d9b17da7 Code: f0 ff ff 73 01 c3 48 8b 0d 7e 90 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 51 90 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007fff586b8078 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f17d9b17da7 RDX: 0000000000000000 RSI: 0000557f331aa510 RDI: 00007fff586b8098 RBP: 0000557f331ea040 R08: 0000000000000000 R09: 042dc9cc5c57b4e0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff586b8098 R14: 0000557f331aa500 R15: 0000557efbeab160 rcu: rcu_preempt kthread starved for 10412 jiffies! g29765 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:28424 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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: 1 UID: 0 PID: 10795 Comm: syz.2.1387 Not tainted 6.13.0-rc2-syzkaller-00031-gf92f4749861b #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+0x458/0x1300 kernel/smp.c:884 Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 aa 0d 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 a7 0c 00 00 8b 43 08 31 RSP: 0018:ffffc9000bb77b30 EFLAGS: 00000246 RAX: 0000000000080000 RBX: ffff8880b86469c0 RCX: ffffc9000cc21000 RDX: 0000000000080000 RSI: ffffffff818df5d6 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000005 R12: ffffed10170c8d39 R13: 0000000000000001 R14: ffff8880b86469c8 R15: ffff8880b873fe40 FS: 00007fa748a3d6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c39450e CR3: 0000000028886000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1051 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2114 [inline] text_poke_bp_batch+0x22b/0x760 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_flush arch/x86/kernel/alternative.c:2512 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 __sched_core_enable kernel/sched/core.c:432 [inline] sched_core_get+0x8a/0xa0 kernel/sched/core.c:456 sched_core_alloc_cookie kernel/sched/core_sched.c:18 [inline] sched_core_share_pid+0x41f/0xa00 kernel/sched/core_sched.c:185 __do_sys_prctl+0x15e6/0x2190 kernel/sys.c:2741 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa747b7ff19 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:00007fa748a3d058 EFLAGS: 00000246 ORIG_RAX: 000000000000009d RAX: ffffffffffffffda RBX: 00007fa747d45fa0 RCX: 00007fa747b7ff19 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000003e RBP: 00007fa747bf3cc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa747d45fa0 R15: 00007ffe3b8fd5a8