rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=777c/1/0x4000000000000000 softirq=7490/7496 fqs=3 rcu: (detected by 1, t=10502 jiffies, g=7321, q=1532 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5122 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-12393-g9b62e02e6336 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:589 [inline] RIP: 0010:queued_spin_unlock arch/x86/include/asm/qspinlock.h:57 [inline] RIP: 0010:do_raw_spin_unlock+0x118/0x8b0 kernel/locking/spinlock_debug.c:142 Code: 49 c7 45 00 ff ff ff ff 0f b6 04 2b 84 c0 0f 85 cf 03 00 00 41 c7 06 ff ff ff ff 48 c7 c0 e0 fd 19 8e 48 c1 e8 03 80 3c 28 00 <74> 0c 48 c7 c7 e0 fd 19 8e e8 0a 18 88 00 48 83 3d 02 3f a6 0c 00 RSP: 0018:ffffc90000007c60 EFLAGS: 00000046 RAX: 1ffffffff1c33fbc RBX: 1ffff11017285911 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880b942c880 RBP: dffffc0000000000 R08: ffff8880b942c883 R09: 1ffff11017285910 R10: dffffc0000000000 R11: ffffed1017285911 R12: 1ffff11017285912 R13: ffff8880b942c890 R14: ffff8880b942c888 R15: ffff8880b942c880 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f5e71560 CR3: 000000000e132000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock_irqrestore+0x81/0x140 kernel/locking/spinlock.c:194 __run_hrtimer kernel/time/hrtimer.c:1683 [inline] __hrtimer_run_queues+0x477/0xd50 kernel/time/hrtimer.c:1751 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1813 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 ee d3 6a f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 c3 87 d4 f5 65 8b 05 f4 d1 72 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc90003f27660 EFLAGS: 00000206 RAX: add48288cf8d8a00 RBX: 1ffff920007e4ed0 RCX: ffffffff947a0603 RDX: dffffc0000000000 RSI: ffffffff8bcaba80 RDI: 0000000000000001 RBP: ffffc90003f276f0 R08: ffffffff8fad43af R09: 1ffffffff1f5a875 R10: dffffc0000000000 R11: fffffbfff1f5a876 R12: dffffc0000000000 R13: 1ffff920007e4ecc R14: ffffc90003f27680 R15: 0000000000000246 __debug_check_no_obj_freed lib/debugobjects.c:998 [inline] debug_check_no_obj_freed+0x561/0x580 lib/debugobjects.c:1019 remove_vm_area+0x1d3/0x300 mm/vmalloc.c:3205 vfree+0x7c/0x2e0 mm/vmalloc.c:3328 kcov_put kernel/kcov.c:429 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:525 __fput+0x406/0x8b0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa27/0x27e0 kernel/exit.c:874 do_group_exit+0x207/0x2c0 kernel/exit.c:1023 get_signal+0x16a1/0x1740 kernel/signal.c:2909 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 __do_fast_syscall_32+0xc4/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7253579 Code: Unable to access opcode bytes at 0xf725354f. RSP: 002b:00000000f74f5d44 EFLAGS: 00000206 ORIG_RAX: 0000000000000036 RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 0000000000004c01 RDX: 0000000000000000 RSI: 00000000f73aaff4 RDI: 00000000f73aaff4 RBP: 0000000000000bb8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10487 jiffies! g7321 f0x0 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:25168 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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: 1 PID: 2854 Comm: kworker/u8:8 Not tainted 6.9.0-syzkaller-12393-g9b62e02e6336 #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+0x1860/0x29d0 kernel/smp.c:855 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 99 09 0c 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 44 05 0c 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 28 05 RSP: 0018:ffffc90009757700 EFLAGS: 00000293 RAX: ffffffff818a1158 RBX: 1ffff11017288c11 RCX: ffff88802b39da00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900097578e0 R08: ffffffff818a1127 R09: 1ffffffff25f50b0 R10: dffffc0000000000 R11: fffffbfff25f50b1 R12: dffffc0000000000 R13: ffff8880b9446088 R14: ffff8880b953f900 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561afabb3680 CR3: 000000000e132000 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:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2069 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2279 text_poke_flush arch/x86/kernel/alternative.c:2470 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2477 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:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244