rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...0: (1 GPs behind) idle=5174/1/0x4000000000000000 softirq=69756/69757 fqs=2871 (detected by 0, t=10502 jiffies, g=100337, q=300 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2997 Comm: udevd Not tainted 6.1.0-syzkaller-00071-g3a28c2c89f4b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:121 [inline] RIP: 0010:rcu_is_watching+0x36/0xb0 kernel/rcu/tree.c:713 Code: e8 0f 30 32 09 89 c3 83 f8 08 73 75 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 40 28 e0 8c 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 d0 7d 6c 00 48 c7 c3 a8 4a 03 00 49 03 1e 48 89 RSP: 0018:ffffc900001e0a60 EFLAGS: 00000046 RAX: 1ffffffff19c0509 RBX: 0000000000000001 RCX: ffff88807ce6d7c0 RDX: 0000000000000000 RSI: ffffffff8b6905a0 RDI: ffffffff8b690560 RBP: ffffc900001e0b00 R08: dffffc0000000000 R09: fffffbfff1d1f58e R10: fffffbfff1d1f58e R11: 1ffffffff1d1f58d R12: dffffc0000000000 R13: ffffffff817bd249 R14: ffffffff8ce02848 R15: dffffc0000000000 FS: 00007f68ebbbf840(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f322e0d56be CR3: 0000000029185000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:108 [inline] rcu_read_lock_sched_held+0x6b/0x130 kernel/rcu/update.c:123 trace_lock_release+0x95/0x220 include/trace/events/lock.h:69 lock_release+0x81/0x870 kernel/locking/lockdep.c:5679 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x75/0x130 kernel/locking/spinlock.c:194 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline] debug_deactivate kernel/time/hrtimer.c:481 [inline] __run_hrtimer kernel/time/hrtimer.c:1653 [inline] __hrtimer_run_queues+0x2f9/0xa60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3a6/0xfd0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline] __sysvec_apic_timer_interrupt+0xf9/0x280 arch/x86/kernel/apic/apic.c:1113 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:get_any_partial+0xd5/0x1b0 mm/slub.c:2294 Code: 75 00 4d 85 f6 0f 84 aa 00 00 00 66 2e 0f 1f 84 00 00 00 00 00 41 8b 5e 58 48 83 fb 40 73 62 48 63 c3 4d 8b a4 c7 d0 00 00 00 <4d> 85 e4 74 28 8b 72 08 eb 62 49 8b 44 24 40 49 3b 47 10 76 18 4c RSP: 0018:ffffc9000ccf7c48 EFLAGS: 00000287 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffffc9000ccf7cd0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88813fffc300 R08: ffffffff81de45a1 R09: fffffbfff1d1f58e R10: fffffbfff1d1f58e R11: 1ffffffff1d1f58d R12: ffff8880129e1480 R13: 0000000000000002 R14: ffff88813fffae00 R15: ffff8880129e0780 get_partial mm/slub.c:2329 [inline] ___slab_alloc+0x79a/0xeb0 mm/slub.c:3175 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x24c/0x300 mm/slub.c:3422 getname_flags+0xb8/0x4e0 fs/namei.c:139 user_path_at_empty+0x2a/0x1a0 fs/namei.c:2875 do_readlinkat+0x11b/0x3b0 fs/stat.c:468 __do_sys_readlink fs/stat.c:501 [inline] __se_sys_readlink fs/stat.c:498 [inline] __x64_sys_readlink+0x7b/0x90 fs/stat.c:498 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f68ebfa7277 Code: 73 01 c3 48 8b 0d 01 dc 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d d1 db 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc35f56bc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffc35f56bd8 RCX: 00007f68ebfa7277 RDX: 0000000000000400 RSI: 00007ffc35f56bd8 RDI: 00007ffc35f570b8 RBP: 0000000000000400 R08: 00000000003fffff R09: 000055addfdba290 R10: 00007f68ec034fc0 R11: 0000000000000246 R12: 00007ffc35f570b8 R13: 00007ffc35f57028 R14: 000055addfb94910 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 4757 jiffies! g100337 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:26552 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5209 [inline] __schedule+0x8fc/0xda0 kernel/sched/core.c:6521 schedule+0xcb/0x190 kernel/sched/core.c:6597 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x309/0x1070 kernel/rcu/tree.c:1654 rcu_gp_kthread+0xa5/0x390 kernel/rcu/tree.c:1853 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.0-syzkaller-00071-g3a28c2c89f4b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:113 [inline] RIP: 0010:acpi_idle_do_entry drivers/acpi/processor_idle.c:572 [inline] RIP: 0010:acpi_idle_enter+0x43d/0x800 drivers/acpi/processor_idle.c:709 Code: ff e8 f7 1d dc f6 48 83 e3 08 44 8b 7c 24 04 0f 85 00 01 00 00 e8 03 df e2 f6 66 90 e8 1c 19 dc f6 0f 00 2d 75 9b c3 00 fb f4 <4c> 89 e3 48 c1 eb 03 42 80 3c 2b 00 74 08 4c 89 e7 e8 fd 1b 31 f7 RSP: 0018:ffffffff8d007b80 EFLAGS: 000002d3 RAX: ffffffff8ab08244 RBX: 0000000000000000 RCX: ffffffff8d0bb7c0 RDX: 0000000000000000 RSI: ffffffff8b0d91a0 RDI: ffffffff8b6905c0 RBP: ffffffff8d007c30 R08: ffffffff8ab08229 R09: fffffbfff1a176f9 R10: fffffbfff1a176f9 R11: 1ffffffff1a176f8 R12: ffffffff8d007bc0 R13: dffffc0000000000 R14: ffff888145980000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c032848000 CR3: 00000000295f9000 CR4: 00000000003506f0 Call Trace: cpuidle_enter_state+0x50b/0xf50 drivers/cpuidle/cpuidle.c:239 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x3da/0x680 kernel/sched/idle.c:303 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:400 rest_init+0x24f/0x270 init/main.c:729 arch_call_rest_init+0xa/0xa init/main.c:890 start_kernel+0x4b1/0x560 init/main.c:1145 secondary_startup_64_no_verify+0xcf/0xdb