rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (2 ticks this GP) idle=4984/1/0x4000000000000000 softirq=119645/119646 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P24683/1:b..l rcu: (detected by 0, t=10504 jiffies, g=191037, q=330 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3 Comm: pool_workqueue_ Not tainted 6.9.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x36/0xc0 kernel/rcu/tree.c:700 Code: 7e e8 ae 99 67 09 48 c7 c3 e8 7e 03 00 83 f8 07 89 c5 0f 87 82 00 00 00 48 8d 3c ed 40 1b 46 8d 48 b8 00 00 00 00 00 fc ff df <48> 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed 40 1b 46 8d 48 RSP: 0018:ffffc90000a08c68 EFLAGS: 00000097 RAX: dffffc0000000000 RBX: 0000000000037ee8 RCX: ffffffff816bf72b RDX: fffffbfff1f7eaf3 RSI: ffffffff8b8f5820 RDI: ffffffff8d461b48 RBP: 0000000000000001 R08: 0000000000000000 R09: fffffbfff1f7eaf2 R10: ffffffff8fbf5797 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000000 R14: ffff88802e435300 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000011678000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x47b/0x560 kernel/locking/lockdep.c:5725 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xd8/0xc60 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x20c/0xcc0 kernel/time/hrtimer.c:1756 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1818 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x10f/0x450 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lockdep_unregister_key+0x1ab/0x280 kernel/locking/lockdep.c:6476 Code: 51 fd 93 48 89 df e8 54 fd ff ff 48 89 df e8 5c d9 ff ff e8 57 db ff ff 9c 58 f6 c4 02 75 66 41 f7 c5 00 02 00 00 74 01 fb 5b <5d> 41 5c 41 5d 41 5e 41 5f e9 37 13 0a 00 48 c7 c0 58 8b bf 8f 48 RSP: 0018:ffffc90000087df8 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffff8880603590e8 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8b2cb0a0 RDI: ffffffff8b8f58a0 RBP: ffff88805dd1e138 R08: 0000000000000007 R09: 000000001fffffff R10: 0000000013fd5120 R11: ffffffff8b2e3540 R12: 0000000000000000 R13: 0000000000000246 R14: ffffffff94176808 R15: ffff88805dd1e140 wq_unregister_lockdep kernel/workqueue.c:4668 [inline] pwq_release_workfn+0x539/0x9d0 kernel/workqueue.c:4971 kthread_worker_fn+0x305/0xb20 kernel/kthread.c:841 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 task:syz-executor.2 state:R running task stack:27720 pid:24683 tgid:24682 ppid:21327 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7068 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire+0x1f2/0x560 kernel/locking/lockdep.c:5722 Code: c1 05 0a 93 96 7e 83 f8 01 0f 85 ea 02 00 00 9c 58 f6 c4 02 0f 85 d5 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0000:ffffc900035afdf0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920006b5fc0 RCX: 00000000963b3129 RDX: 0000000000000001 RSI: ffffffff8b2cb0e0 RDI: ffffffff8b8f58a0 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff27fca30 R10: ffffffff93fe5187 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8d9b0e20 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:329 [inline] rcu_read_lock include/linux/rcupdate.h:781 [inline] vma_end_read include/linux/mm.h:700 [inline] do_user_addr_fault+0x672/0x1030 arch/x86/mm/fault.c:1333 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f228dc29786 RSP: 002b:00007f228ea0b530 EFLAGS: 00010206 RAX: 0000000000d11001 RBX: 00007f228ea0b5d0 RCX: 00000000000000b2 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f228ea0b670 RBP: 0000000000000102 R08: 00007f2283a00000 R09: 0000000000d11000 R10: 0000000000000000 R11: 00007f228ea0b5e0 R12: 0000000000000001 R13: 00007f228dcecfe0 R14: 0000000000000000 R15: 00007f228ea0b670 rcu: rcu_preempt kthread timer wakeup didn't happen for 10503 jiffies! g191037 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=92946 rcu: rcu_preempt kthread starved for 10504 jiffies! g191037 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27568 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6838 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:1663 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:1862 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244