rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=e444/1/0x4000000000000000 softirq=93806/93807 fqs=0 rcu: (detected by 0, t=10506 jiffies, g=131481, q=171 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 27644 Comm: syz-executor.2 Not tainted 6.6.0-rc5-syzkaller-00171-gce583d5fb9d3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:32 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:67 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:lock_acquire+0x22d/0x520 kernel/locking/lockdep.c:5756 Code: 0f 85 a4 01 00 00 49 89 de 48 c1 eb 03 42 80 3c 2b 00 74 08 4c 89 f7 e8 e1 96 7b 00 48 c7 44 24 60 00 00 00 00 9c 8f 44 24 60 <42> 80 3c 2b 00 74 08 4c 89 f7 e8 24 96 7b 00 f6 44 24 61 02 0f 85 RSP: 0018:ffffc900001f0a00 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff9200003e14c RCX: ffffffff816d0c65 RDX: 0000000000000000 RSI: ffffffff8b0ab620 RDI: ffffffff8b5982e0 RBP: ffffc900001f0b48 R08: dffffc0000000000 R09: 1ffffffff20dee70 R10: dffffc0000000000 R11: fffffbfff20dee71 R12: 1ffff9200003e148 R13: dffffc0000000000 R14: ffffc900001f0a60 R15: 0000000000000046 FS: 00007f308ea7a6c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f308dd9c000 CR3: 00000000246bb000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 debug_object_activate+0x163/0x530 lib/debugobjects.c:717 debug_hrtimer_activate kernel/time/hrtimer.c:422 [inline] debug_activate kernel/time/hrtimer.c:477 [inline] enqueue_hrtimer+0x30/0x310 kernel/time/hrtimer.c:1087 __run_hrtimer kernel/time/hrtimer.c:1705 [inline] __hrtimer_run_queues+0x6c0/0xd10 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x396/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1063 [inline] __sysvec_apic_timer_interrupt+0x104/0x390 arch/x86/kernel/apic/apic.c:1080 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1074 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:finish_task_switch+0x1d3/0x830 kernel/sched/core.c:5254 Code: 8b 0b 00 48 83 c4 08 4c 89 f7 e8 68 31 00 00 0f 1f 44 00 00 4c 89 f7 e8 3b 9d 77 09 e8 16 77 33 00 fb 49 8d bc 24 e0 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28 RSP: 0018:ffffc9000e887eb0 EFLAGS: 00000282 RAX: 9db63bb283852a00 RBX: ffff888020673bb4 RCX: ffffffff91eef303 RDX: dffffc0000000000 RSI: ffffffff8b0aa4a0 RDI: ffff88801fea6f20 RBP: ffffc9000e887ef8 R08: ffffffff8e9a30ef R09: 1ffffffff1d3461d R10: dffffc0000000000 R11: fffffbfff1d3461e R12: ffff88801fea5940 R13: 1ffff11017327a0b R14: ffff8880b993c300 R15: ffff8880b993d058 schedule_tail+0xf/0xb0 kernel/sched/core.c:5311 ret_from_fork+0x24/0x80 arch/x86/kernel/process.c:143 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 rcu: rcu_preempt kthread starved for 10506 jiffies! g131481 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:26504 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x196c/0x4af0 kernel/sched/core.c:6695 schedule+0xc3/0x180 kernel/sched/core.c:6771 schedule_timeout+0x1bd/0x300 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x2c6/0x1010 kernel/rcu/tree.c:1613 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1812 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 27642 Comm: syz-executor.2 Not tainted 6.6.0-rc5-syzkaller-00171-gce583d5fb9d3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 RIP: 0010:csd_lock_wait kernel/smp.c:300 [inline] RIP: 0010:smp_call_function_many_cond+0x1805/0x2890 kernel/smp.c:844 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 34 59 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 6f 55 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 53 55 RSP: 0000:ffffc9000e857580 EFLAGS: 00000293 RAX: ffffffff8182b68d RBX: 1ffff110173282cd RCX: ffff88801de59dc0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000e857780 R08: ffffffff8182b65c R09: 1ffffffff20dee70 R10: dffffc0000000000 R11: fffffbfff20dee71 R12: dffffc0000000000 R13: ffff8880b9941668 R14: ffff8880b983d440 R15: 0000000000000001 FS: 0000555555b1d480(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001700 CR3: 00000000246bb000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1012 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline] flush_tlb_multi arch/x86/mm/tlb.c:944 [inline] flush_tlb_mm_range+0x330/0x5c0 arch/x86/mm/tlb.c:1030 flush_tlb_page arch/x86/include/asm/tlbflush.h:254 [inline] ptep_clear_flush+0x11a/0x170 mm/pgtable-generic.c:101 wp_page_copy mm/memory.c:3142 [inline] do_wp_page+0x221e/0x4190 mm/memory.c:3449 handle_pte_fault mm/memory.c:4994 [inline] __handle_mm_fault mm/memory.c:5119 [inline] handle_mm_fault+0x1b45/0x62b0 mm/memory.c:5284 do_user_addr_fault arch/x86/mm/fault.c:1364 [inline] handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x455/0x860 arch/x86/mm/fault.c:1561 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x7f308dc36283 Code: 8b 4c 24 40 c6 40 20 01 89 48 24 8b 4c 24 4c 44 89 68 28 44 89 50 2c 89 48 78 40 88 7c 1a 04 8b 5c 24 44 4c 89 3d ed 5c 16 00 <89> 98 80 00 00 00 0f 1f 80 00 00 00 00 48 8b 94 2c a0 01 00 00 48 RSP: 002b:00007ffe2dcbf410 EFLAGS: 00010246 RAX: 00007f308dd9bf80 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 00007f308dd9bff8 RSI: 00007f308dd9bf88 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f308dd9bf8c R10: 0000000000000005 R11: 0000000000000246 R12: 00007f308dd9bf80 R13: 0000000000000b6d R14: 0000000000000000 R15: 00007f308dd9bf80