rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10503 jiffies, g=159085, q=48 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10501 (4295110104-4295099603), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10501 jiffies! g159085 f0x2 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:28368 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5184 [inline] __schedule+0xa09/0x4f10 kernel/sched/core.c:6496 schedule+0xd2/0x1f0 kernel/sched/core.c:6568 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1657 rcu_gp_kthread+0x234/0x360 kernel/rcu/tree.c:1854 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 28482 Comm: kworker/1:7 Not tainted 5.19.0-rc4-next-20220628-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: events pwq_unbound_release_workfn RIP: 0010:mark_lock.part.0+0x158/0x1910 kernel/locking/lockdep.c:4591 Code: 70 50 0f 84 d3 06 00 00 41 ba 01 00 00 00 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> c7 43 14 00 00 00 00 48 8b 84 24 30 01 00 00 65 48 2b 04 25 28 RSP: 0018:ffffc900001e0980 EFLAGS: 00000082 RAX: dffffc0000000000 RBX: fffff5200003c137 RCX: 1ffffffff20d4bb6 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff906a5db0 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff906a5947 R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880247a4548 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880247a4568 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000140 CR3: 0000000048599000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_lock kernel/locking/lockdep.c:4596 [inline] mark_usage kernel/locking/lockdep.c:4524 [inline] __lock_acquire+0x14ad/0x5660 kernel/locking/lockdep.c:5007 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 debug_object_deactivate lib/debugobjects.c:739 [inline] debug_object_deactivate+0x101/0x300 lib/debugobjects.c:727 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+0x3f3/0xe40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lockdep_unregister_key+0x279/0x460 kernel/locking/lockdep.c:6358 Code: e8 ec ea ff ff 4c 89 e7 e8 e4 c6 ff ff e8 8f c7 ff ff 9c 58 f6 c4 02 0f 85 43 01 00 00 41 f7 c6 00 02 00 00 0f 85 ec 00 00 00 82 65 08 00 48 b8 00 00 00 00 00 fc ff df 49 c7 44 05 00 00 00 RSP: 0018:ffffc90015f97c38 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffff888029dc9128 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888029dc9128 R08: 0000000000000001 R09: ffffffff8f3a3db0 R10: fffffbfff20d40a3 R11: 00000000000633d8 R12: ffffffff9069d908 R13: 1ffff92002bf2f88 R14: 0000000000000246 R15: ffffffff9082c600 wq_unregister_lockdep kernel/workqueue.c:3499 [inline] pwq_unbound_release_workfn+0x254/0x340 kernel/workqueue.c:3737 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 ---------------- Code disassembly (best guess): 0: 70 50 jo 0x52 2: 0f 84 d3 06 00 00 je 0x6db 8: 41 ba 01 00 00 00 mov $0x1,%r10d e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 15: fc ff df 18: 48 01 c3 add %rax,%rbx 1b: 48 c7 03 00 00 00 00 movq $0x0,(%rbx) 22: 48 c7 43 08 00 00 00 movq $0x0,0x8(%rbx) 29: 00 * 2a: 48 c7 43 14 00 00 00 movq $0x0,0x14(%rbx) <-- trapping instruction 31: 00 32: 48 8b 84 24 30 01 00 mov 0x130(%rsp),%rax 39: 00 3a: 65 gs 3b: 48 rex.W 3c: 2b .byte 0x2b 3d: 04 25 add $0x25,%al 3f: 28 .byte 0x28