rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=dc74/1/0x4000000000000000 softirq=52823/52824 fqs=5 rcu: (detected by 1, t=10502 jiffies, g=77485, q=466 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 14910 Comm: syz-executor.3 Not tainted 6.9.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:check_preemption_disabled+0x3c/0x120 Code: 00 00 48 89 44 24 08 65 8b 1d 7c 88 83 74 65 8b 05 71 88 83 74 a9 ff ff ff 7f 74 26 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 <0f> 85 ce 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f e9 87 f5 RSP: 0018:ffffc900000079e8 EFLAGS: 00000046 RAX: aeb5ea12fe0bfc00 RBX: 0000000000000000 RCX: ffffc90000007a03 RDX: 0000000000000001 RSI: ffffffff8bcaca00 RDI: ffffffff8c1f7fe0 RBP: ffffc90000007b50 R08: ffffffff8fa8f72f R09: 1ffffffff1f51ee5 R10: dffffc0000000000 R11: fffffbfff1f51ee6 R12: 1ffff92000000f50 R13: 0000000000000046 R14: ffffc90000007ab0 R15: dffffc0000000000 FS: 00007f4e06f5f6c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32a21000 CR3: 0000000079458000 CR4: 0000000000350ef0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_release+0x5c4/0x9f0 kernel/locking/lockdep.c:5776 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x79/0x140 kernel/locking/spinlock.c:194 debug_object_activate+0x3e4/0x510 lib/debugobjects.c:726 debug_hrtimer_activate kernel/time/hrtimer.c:423 [inline] debug_activate kernel/time/hrtimer.c:478 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1090 __run_hrtimer kernel/time/hrtimer.c:1709 [inline] __hrtimer_run_queues+0x6d5/0xd50 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:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:67 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:103 [inline] RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] RIP: 0010:_raw_spin_lock_irqsave+0x75/0x120 kernel/locking/spinlock.c:162 Code: c7 44 24 10 50 f7 8a 8b 49 89 e5 49 c1 ed 03 48 b8 f1 f1 f1 f1 00 f3 f3 f3 4b 89 44 3d 00 4c 89 e3 48 c1 eb 03 42 80 3c 3b 00 <74> 08 4c 89 e7 e8 81 bc 6f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 RSP: 0018:ffffc90009b279a0 EFLAGS: 00000246 RAX: f3f3f300f1f1f1f1 RBX: 1ffff92001364f38 RCX: 61c8864680b583eb RDX: 0000000000000001 RSI: ffffc90009b27b00 RDI: ffffffff9495aa38 RBP: ffffc90009b27a30 R08: ffffc90009b27b07 R09: ffffc90009b27ae0 R10: dffffc0000000000 R11: fffff52001364f61 R12: ffffc90009b279c0 R13: 1ffff92001364f34 R14: ffffffff9495aa38 R15: dffffc0000000000 __debug_check_no_obj_freed lib/debugobjects.c:978 [inline] debug_check_no_obj_freed+0x234/0x580 lib/debugobjects.c:1019 slab_free_hook mm/slub.c:2078 [inline] slab_free mm/slub.c:4280 [inline] kfree+0x119/0x3a0 mm/slub.c:4390 raw_ioctl+0x2253/0x3ce0 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0xfe/0x170 fs/ioctl.c:890 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: 0033:0x7f4e0627da0b Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007f4e06f5e000 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000088 RCX: 00007f4e0627da0b RDX: 00007f4e06f5e080 RSI: 0000000040085507 RDI: 0000000000000005 RBP: 0000000000000005 R08: 00007f4e064d0320 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000020000240 R13: 000000000000000a R14: 00007f4e063abf80 R15: 00007ffcc0267878 rcu: rcu_preempt kthread starved for 10491 jiffies! g77485 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:24912 pid:16 tgid:16 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:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 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: 1 PID: 2886 Comm: kworker/u8:9 Not tainted 6.9.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 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 15 db 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 c0 d6 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 a4 d6 0b 00 eb e4 44 RSP: 0018:ffffc9000a2976e0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff11017288c6d RCX: ffff88802bc50000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000a2978e0 R08: ffffffff818a31ab R09: 1ffffffff25e6aa0 R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: dffffc0000000000 R13: ffff8880b9446368 R14: ffff8880b953f7c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcc67978198 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