rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=d61/1/0x4000000000000000 softirq=29446/29447 fqs=3 (detected by 1, t=10502 jiffies, g=39701, q=86) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8781 Comm: syz.1.572 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:99 [inline] RIP: 0010:do_raw_spin_unlock+0x1b/0x230 kernel/locking/spinlock_debug.c:140 Code: ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 55 41 57 41 56 41 55 41 54 53 48 89 fb 49 bc 00 00 00 00 00 fc ff df 4c 8d 77 04 <4c> 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 7f 01 00 00 41 81 RSP: 0018:ffffc900048bfc88 EFLAGS: 00000046 RAX: 9b7a94dbf1b97b00 RBX: ffffffff8c900420 RCX: 9b7a94dbf1b97b00 RDX: 0000000000000001 RSI: ffffffff8a0b2860 RDI: ffffffff8c900420 RBP: ffffc900048bfd50 R08: dffffc0000000000 R09: fffffbfff1ad2dd6 R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: dffffc0000000000 R13: ffff88802b827824 R14: ffffffff8c900424 R15: 1ffff92000917f98 FS: 0000555581eea500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000001a4000 CR3: 000000007699d000 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:159 [inline] _raw_spin_unlock_irqrestore+0x75/0x100 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline] vga_put drivers/gpu/vga/vgaarb.c:564 [inline] vga_arb_release+0x40b/0xa90 drivers/gpu/vga/vgaarb.c:1350 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc7c5f349a9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcd4407a78 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000048828 RCX: 00007fc7c5f349a9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fc7c615dba0 R08: 0000000000000001 R09: 00000018d4407d6f R10: 00007fc7c5da6000 R11: 0000000000000246 R12: 00007fc7c615c08c R13: 00007fc7c615c080 R14: ffffffffffffffff R15: 00007ffcd4407b90 rcu: rcu_preempt kthread starved for 10496 jiffies! g39701 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:28000 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 4234 Comm: kworker/1:4 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events bpf_prog_free_deferred Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1690 [inline] __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0xb88/0xd70 kernel/smp.c:969 Code: b6 44 05 00 84 c0 0f 85 9d 00 00 00 41 8b 1c 24 89 de 83 e6 01 31 ff e8 a6 46 0b 00 83 e3 01 75 07 e8 3c 43 0b 00 eb 43 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 11 41 f7 RSP: 0018:ffffc900031ef840 EFLAGS: 00000293 RAX: ffffffff816c810b RBX: 0000000000000001 RCX: ffff888029890000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900031ef980 R08: dffffc0000000000 R09: fffffbfff1ff6e1a R10: fffffbfff1ff6e1a R11: 1ffffffff1ff6e19 R12: ffff8880b9042a08 R13: 1ffff11017208541 R14: ffff8880b913b380 R15: 0000000000000000 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135 __purge_vmap_area_lazy+0x216/0x18f0 mm/vmalloc.c:1683 _vm_unmap_aliases+0x410/0x4a0 mm/vmalloc.c:2107 vm_remove_mappings mm/vmalloc.c:2584 [inline] __vunmap+0x70d/0xa40 mm/vmalloc.c:2611 bpf_jit_binary_free kernel/bpf/core.c:918 [inline] bpf_jit_free+0x92/0x180 kernel/bpf/core.c:931 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287