rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=3f5c/1/0x4000000000000000 softirq=58922/58923 fqs=0 (detected by 0, t=10505 jiffies, g=82253, q=26 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 17916 Comm: syz-executor.2 Not tainted 6.1.35-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 RIP: 0010:__lock_release kernel/locking/lockdep.c:5327 [inline] RIP: 0010:lock_release+0x1db/0xa20 kernel/locking/lockdep.c:5689 Code: 42 0f b6 04 3b 84 c0 0f 85 6e 05 00 00 c7 84 24 80 00 00 00 01 00 00 00 48 c7 c0 24 5f 53 8e 48 c1 e8 03 42 0f b6 04 38 84 c0 <4c> 8b 74 24 10 0f 85 6e 05 00 00 83 3d d7 64 e9 0c 00 0f 84 c4 03 RSP: 0018:ffffc900001e0b60 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 1ffff9200003c17c RCX: ffffc900001e0b03 RDX: 0000000000000000 RSI: ffffffff8aebde80 RDI: ffffffff8b3ccb60 RBP: ffffc900001e0c90 R08: dffffc0000000000 R09: fffffbfff1ca654e R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200003c178 R13: 0000000000000046 R14: ffffc900001e0c10 R15: dffffc0000000000 FS: 00007fd7a8926700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000280 CR3: 0000000021f69000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __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+0x1d/0x280 kernel/time/hrtimer.c:481 __run_hrtimer kernel/time/hrtimer.c:1653 [inline] __hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: 41 35 f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ae a7 dc f6 48 89 df e8 06 e4 dd f6 e8 d1 37 03 f7 fb bf 01 00 00 00 a6 a2 d0 f6 65 8b 05 77 1e 75 75 85 c0 74 02 5b c3 e8 74 3c 73 RSP: 0018:ffffc9000cb8fd20 EFLAGS: 00000282 RAX: b01ab34b3276e500 RBX: ffff888085b4d488 RCX: ffffffff91a83103 RDX: dffffc0000000000 RSI: ffffffff8aebd1a0 RDI: 0000000000000001 RBP: 00000000ffffff83 R08: dffffc0000000000 R09: ffffed1010b69a92 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888085b4d400 R13: 7fffffffffffffff R14: ffff888085b4d480 R15: 0000000000000003 spin_unlock_irq include/linux/spinlock.h:400 [inline] do_timerfd_settime+0xd1a/0x1000 fs/timerfd.c:521 __do_sys_timerfd_settime fs/timerfd.c:567 [inline] __se_sys_timerfd_settime fs/timerfd.c:558 [inline] __x64_sys_timerfd_settime+0x16b/0x220 fs/timerfd.c:558 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fd7a7c8c389 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd7a8926168 EFLAGS: 00000246 ORIG_RAX: 000000000000011e RAX: ffffffffffffffda RBX: 00007fd7a7dabf80 RCX: 00007fd7a7c8c389 RDX: 0000000020000100 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00007fd7a7cd7493 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc5ff0bc1f R14: 00007fd7a8926300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10505 jiffies! g82253 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:26712 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x132c/0x4330 kernel/sched/core.c:6554 schedule+0xbf/0x180 kernel/sched/core.c:6630 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x2c2/0x1010 kernel/rcu/tree.c:1661 rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1860 kthread+0x26e/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: 57 Comm: kworker/u4:4 Not tainted 6.1.35-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:413 [inline] RIP: 0010:smp_call_function_many_cond+0x1f62/0x33d0 kernel/smp.c:987 Code: 2f 44 89 ee 83 e6 01 31 ff e8 6a 0c 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 f5 08 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff RSP: 0018:ffffc900015875a0 EFLAGS: 00000293 RAX: ffffffff817ecdbd RBX: 1ffff11017328021 RCX: ffff8880186dbb80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90001587980 R08: ffffffff817ecd86 R09: fffffbfff2051645 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b9940108 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd12cf33718 CR3: 000000000cc8e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1155 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1316 [inline] text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1516 text_poke_flush arch/x86/kernel/alternative.c:1707 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1714 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804 process_one_work+0x8aa/0x11f0 kernel/workqueue.c:2289 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436 kthread+0x26e/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306