rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=d504/1/0x4000000000000000 softirq=26392/26393 fqs=2
	(detected by 1, t=10506 jiffies, g=31817, q=64 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8064 Comm: syz.5.1202 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:lock_release+0x6/0x920 kernel/locking/lockdep.c:5798
Code: 03 38 c1 0f 8c 67 fa ff ff 4c 89 f7 e8 d3 1e 6f 00 e9 5a fa ff ff 41 be 2f 00 00 00 e9 70 fa ff ff 0f 1f 00 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00 00 48 89 74 24
RSP: 0018:ffffc90000007ca8 EFLAGS: 00000096
RAX: 1ffff1100d14f065 RBX: ffff888068a782e8 RCX: ffffffff88697175
RDX: 0000000000000001 RSI: ffffffff886971bf RDI: ffff888068a78300
RBP: ffffc90000007cb0 R08: ffff88807e4d25a3 R09: 1ffff1100fc9a4b4
R10: dffffc0000000000 R11: ffffed100fc9a4b5 R12: 18de55c62748bcc0
R13: dffffc0000000000 R14: ffff88807e4d2580 R15: ffff888068a78000
FS:  00007fcccd1176c0(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcccd116ff8 CR3: 0000000056cf4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline]
 _raw_spin_unlock+0x12/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 advance_sched+0x66f/0x950 net/sched/sch_taprio.c:751
 __run_hrtimer kernel/time/hrtimer.c:1751 [inline]
 __hrtimer_run_queues+0x522/0xc90 kernel/time/hrtimer.c:1815
 hrtimer_interrupt+0x399/0x980 kernel/time/hrtimer.c:1877
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> ff c7 1a f7 65 8b 05 c0 77 c4 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90004c37b80 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: 3f84c00a751b1b00
RDX: dffffc0000000000 RSI: ffffffff8a8c19a0 RDI: 0000000000000001
RBP: ffffc90004c37c10 R08: ffffffff91934247 R09: 1ffffffff2326848
R10: dffffc0000000000 R11: fffffbfff2326849 R12: dffffc0000000000
R13: ffff8880b8c2a5c0 R14: ffff8880b8c2a5c0 R15: 1ffff92000986f70
 clock_was_set+0x17c/0x8d0 kernel/time/hrtimer.c:984
 do_settimeofday64+0x597/0x740 kernel/time/timekeeping.c:1345
 __do_sys_clock_settime kernel/time/posix-timers.c:1125 [inline]
 __se_sys_clock_settime kernel/time/posix-timers.c:1113 [inline]
 __x64_sys_clock_settime+0x25a/0x2a0 kernel/time/posix-timers.c:1113
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcccc19e2d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcccd117028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007fcccc425fa0 RCX: 00007fcccc19e2d9
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007fcccc235888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcccc426038 R14: 00007fcccc425fa0 R15: 00007ffd820301a8
 </TASK>
rcu: rcu_preempt kthread starved for 10495 jiffies! g31817 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:27840 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 schedule+0xb9/0x180 kernel/sched/core.c:6639
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 76 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0x1151/0x1250 kernel/smp.c:998
Code: ff e8 53 02 0b 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 0a e8 df fe 0a 00 e9 34 ff ff ff f3 90 41 0f b6 04 1c 84 c0 75 14 <41> f7 07 01 00 00 00 0f 84 17 ff ff ff e8 bd fe 0a 00 eb e1 44 89
RSP: 0018:ffffc900015d7800 EFLAGS: 00000246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888019789e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900015d7960 R08: ffffffff91934247 R09: 1ffffffff2326848
R10: dffffc0000000000 R11: fffffbfff2326849 R12: 1ffff110171885f5
R13: ffff8880b8d3bd80 R14: 0000000000000000 R15: ffff8880b8c42fa8
FS:  0000000000000000(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f826bdb2000 CR3: 000000000d68e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1165
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1574 [inline]
 text_poke_bp_batch+0x2b7/0x850 arch/x86/kernel/alternative.c:1774
 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207
 static_key_enable+0x16/0x20 kernel/jump_label.c:220
 toggle_allocation_gate+0xba/0x470 mm/kfence/core.c:821
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>