rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 ticks this GP) idle=ce7/1/0x4000000000000000 softirq=10163/10163 fqs=34 
	(detected by 0, t=10502 jiffies, g=12393, q=211)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5147 Comm: syz.0.16 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:87 [inline]
RIP: 0010:do_raw_spin_lock+0xe6/0x280 kernel/locking/spinlock_debug.c:114
Code: 39 c8 0f 84 03 01 00 00 4c 8d 6b 08 4d 89 ef 49 c1 ef 03 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 07 84 c0 0f 85 54 01 00 00 <41> 8b 45 00 65 8b 0d 87 dc a4 7e 39 c8 0f 84 ef 00 00 00 c7 44 24
RSP: 0018:ffffc90000dd0b40 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff962e0e50 RCX: ffff88807b1d9dc0
RDX: 0000000000000000 RSI: ffffffff8a0b2460 RDI: ffffffff962e0e50
RBP: ffffc90000dd0bf0 R08: dffffc0000000000 R09: fffffbfff1ff3619
R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: ffffffff962e0e60
R13: ffffffff962e0e58 R14: 1ffffffff2c5c1cc R15: 1ffffffff2c5c1cb
FS:  00007f0692ed86c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000600 CR3: 000000007e0f3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:117 [inline]
 _raw_spin_lock_irqsave+0xb0/0xf0 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x63/0x340 lib/debugobjects.c:749
 debug_hrtimer_deactivate kernel/time/hrtimer.c:415 [inline]
 debug_deactivate+0x1d/0x1c0 kernel/time/hrtimer.c:471
 __run_hrtimer kernel/time/hrtimer.c:1658 [inline]
 __hrtimer_run_queues+0x2db/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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 3e 14 d3 f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 06 94 a6 f7 65 8b 05 a7 a3 57 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90002ebf920 EFLAGS: 00000206
RAX: 28dbfef5b5ce1500 RBX: 0000000000000a06 RCX: 28dbfef5b5ce1500
RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001
RBP: ffffc90002ebf9b0 R08: dffffc0000000000 R09: fffffbfff1ff3619
R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8880b902a200 R15: 1ffff920005d7f24
 clock_was_set+0x642/0x840 kernel/time/hrtimer.c:960
 timekeeping_inject_offset+0x578/0x620 kernel/time/timekeeping.c:1378
 do_adjtimex+0x418/0x9b0 kernel/time/timekeeping.c:2427
 do_clock_adjtime kernel/time/posix-timers.c:1155 [inline]
 __do_sys_clock_adjtime kernel/time/posix-timers.c:1167 [inline]
 __se_sys_clock_adjtime kernel/time/posix-timers.c:1158 [inline]
 __x64_sys_clock_adjtime+0x1f0/0x2a0 kernel/time/posix-timers.c:1158
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0693c68929
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:00007f0692ed8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131
RAX: ffffffffffffffda RBX: 00007f0693e8ffa0 RCX: 00007f0693c68929
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000
RBP: 00007f0693ceab39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0693e8ffa0 R15: 00007fffd3d949e8
 </TASK>
rcu: rcu_preempt kthread starved for 10434 jiffies! g12393 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:27584 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 4365 Comm: kworker/0:7 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:3932 [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
 </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 0a 6b 0b 00 41 83 e6 01 49 bc 00 00 00 00 00 fc ff df 75 0a e8 95 67 0b 00 e9 a3 00 00 00 f3 90 <f7> 44 24 48 01 00 00 00 0f 84 8e 00 00 00 e8 7b 67 0b 00 eb e9 e8
RSP: 0018:ffffc900031ffa40 EFLAGS: 00000293
RAX: ffffffff816c5aa5 RBX: 0000000000000000 RCX: ffff88807bd75940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900031ffb30 R08: dffffc0000000000 R09: ffffed1017227679
R10: ffffed1017227679 R11: 1ffff11017227678 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff9200063ff4c
 rcu_barrier+0x25d/0x4b0 kernel/rcu/tree.c:4078
 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>