rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=7b34/1/0x4000000000000000 softirq=38673/38673 fqs=1 rcu: (detected by 0, t=10502 jiffies, g=55697, q=353 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10032 Comm: syz-executor.5 Not tainted 6.9.0-syzkaller-01768-ga5131c3fdf26 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:mark_lock+0xa2/0x350 kernel/locking/lockdep.c:4656 Code: 00 8b 1b 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 80 15 f4 92 be 08 00 00 00 e8 b6 e1 87 00 48 0f a3 1d 6e f1 80 11 <73> 10 48 69 c3 c8 00 00 00 48 8d 98 80 74 c2 92 eb 68 48 c7 c0 e0 RSP: 0018:ffffc90000a18a28 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 000000000000006b RCX: ffffffff8173240a RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff92f41588 RBP: 0000000000000000 R08: ffffffff92f4158f R09: 1ffffffff25e82b1 R10: dffffc0000000000 R11: fffffbfff25e82b2 R12: 0000000000000001 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff888054b2c6e0 FS: 0000555560695480(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbb5fdbdd58 CR3: 000000006b428000 CR4: 0000000000350ef0 Call Trace: mark_usage kernel/locking/lockdep.c:4564 [inline] __lock_acquire+0xb8e/0x1fd0 kernel/locking/lockdep.c:5091 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1696 [inline] __hrtimer_run_queues+0x67a/0xd50 kernel/time/hrtimer.c:1756 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x112/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5283 Code: c9 50 e8 f9 d0 0b 00 48 83 c4 08 4c 89 f7 e8 ed 38 00 00 0f 1f 44 00 00 4c 89 f7 e8 90 aa 24 0a e8 1b 9f 36 00 fb 48 8b 5d c0 <48> 8d bb f8 15 00 00 48 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc RSP: 0018:ffffc90010037968 EFLAGS: 00000286 RAX: ddf55f108761e400 RBX: ffff888054b2bc00 RCX: ffffffff94739603 RDX: dffffc0000000000 RSI: ffffffff8bcabce0 RDI: ffffffff8c1f9ca0 RBP: ffffc900100379b0 R08: ffffffff8fa9536f R09: 1ffffffff1f52a6d R10: dffffc0000000000 R11: fffffbfff1f52a6e R12: 1ffff110172a7e7f R13: dffffc0000000000 R14: ffff8880b953e680 R15: ffff8880b953f3f8 context_switch kernel/sched/core.c:5412 [inline] __schedule+0x17f0/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2051 hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2104 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1396 [inline] __se_sys_clock_nanosleep+0x32d/0x3c0 kernel/time/posix-timers.c:1373 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f393d2a9175 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 b9 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f ba ff ff 48 8b 04 24 48 83 c4 28 f7 d8 RSP: 002b:00007fff47058d80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000044 RCX: 00007f393d2a9175 RDX: 00007fff47058dc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff47058e4c R08: 0000000000000000 R09: 00007f393dedf0b0 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 000000000006fa7e R14: 000000000006fa52 R15: 0000000000000001 rcu: rcu_preempt kthread starved for 10495 jiffies! g55697 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:24912 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/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: 0 PID: 1260 Comm: kworker/u8:7 Not tainted 6.9.0-syzkaller-01768-ga5131c3fdf26 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1899/0x2a00 kernel/smp.c:855 Code: 89 e6 83 e6 01 31 ff e8 a5 db 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 50 d7 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 34 d7 0b 00 eb e4 44 RSP: 0018:ffffc90004c3f6e0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110172a8871 RCX: ffff888023000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004c3f8e0 R08: ffffffff818a6c6b R09: 1ffffffff25e82b0 R10: dffffc0000000000 R11: fffffbfff25e82b1 R12: dffffc0000000000 R13: ffff8880b9544388 R14: ffff8880b943f7c0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa3c44d66e4 CR3: 000000000e134000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2086 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2296 text_poke_flush arch/x86/kernel/alternative.c:2487 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2494 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:826 process_one_work kernel/workqueue.c:3267 [inline] process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3348 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244