rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=ce7/1/0x4000000000000000 softirq=20684/20685 fqs=0 
	(detected by 0, t=10502 jiffies, g=25005, q=50)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7380 Comm: syz.7.495 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__lock_acquire+0xdc9/0x7c60 kernel/locking/lockdep.c:4982
Code: 48 89 cb 48 8d 3c c5 c0 e0 fb 8f be 08 00 00 00 e8 ec 28 60 00 49 b8 00 00 00 00 00 fc ff df 48 63 c3 48 0f a3 05 d7 d3 9f 0e <0f> 83 23 4f 00 00 49 8d 9d e0 0a 00 00 49 89 de 49 c1 ee 03 43 80
RSP: 0018:ffffc900031ef500 EFLAGS: 00000057
RAX: 0000000000000195 RBX: 0000000000000195 RCX: ffffffff815c0cd4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffbe0f0
RBP: ffffc900031ef750 R08: dffffc0000000000 R09: fffffbfff1ff7c1f
R10: fffffbfff1ff7c1f R11: 1ffffffff1ff7c1e R12: ffff888021bea8f8
R13: ffff888021be9dc0 R14: ffffffff8f9f8bf8 R15: ffff888021bea8d8
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff14c84dfe8 CR3: 000000001e3f2000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 vga_put drivers/gpu/vga/vgaarb.c:558 [inline]
 vga_arb_release+0x231/0xa90 drivers/gpu/vga/vgaarb.c:1350
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x61e/0x20a0 kernel/exit.c:883
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 get_signal+0x6ca/0x12c0 kernel/signal.c:2900
 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 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
 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:280
RIP: 0033:0x7f073e8fde09
Code: Unable to access opcode bytes at RIP 0x7f073e8fdddf.
RSP: 002b:00007f073cacd1c0 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3
RAX: 0000000000000000 RBX: 00007f073e8801f0 RCX: 00007f073e8fde09
RDX: 00007f073e8801f0 RSI: 0000000000000058 RDI: 00007ffc5d258c50
RBP: 00007f073cacd6c0 R08: 00007f073cacd6c0 R09: 00007ffc5d258d37
R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffa8
R13: 000000000000006e R14: 00007ffc5d258c50 R15: 00007ffc5d258d38
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g25005 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:27008 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 4458 Comm: kworker/0:11 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events fqdir_free_fn
Call Trace:
 <IRQ>
 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:1685 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 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
 </IRQ>
 <TASK>
 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_single+0x212/0x490 kernel/smp.c:758
Code: 48 44 89 f6 83 e6 01 31 ff e8 ca 5e 0b 00 41 83 e6 01 49 bc 00 00 00 00 00 fc ff df 75 0a e8 55 5b 0b 00 e9 a3 00 00 00 f3 90 <f7> 44 24 48 01 00 00 00 0f 84 8e 00 00 00 e8 3b 5b 0b 00 eb e9 e8
RSP: 0018:ffffc9000354fa40 EFLAGS: 00000293
RAX: ffffffff816c70d5 RBX: 0000000000000000 RCX: ffff8880298dbb80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000354fb30 R08: dffffc0000000000 R09: ffffed1017227681
R10: ffffed1017227681 R11: 1ffff11017227680 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff920006a9f4c
 rcu_barrier+0x25d/0x4b0 kernel/rcu/tree.c:4082
 fqdir_free_fn+0x2f/0x130 net/ipv4/inet_fragment.c:166
 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
 </TASK>