rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=1144/1/0x4000000000000000 softirq=65421/65424 fqs=1
rcu: 	(detected by 1, t=10502 jiffies, g=52433, q=312 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12900 Comm: syz.0.1787 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:646 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1205 [inline]
RIP: 0010:trace_hrtimer_start include/trace/events/timer.h:222 [inline]
RIP: 0010:debug_activate kernel/time/hrtimer.c:478 [inline]
RIP: 0010:enqueue_hrtimer+0x61/0x3a0 kernel/time/hrtimer.c:1081
Code: 2c 12 00 65 44 8b 3d 22 79 c0 10 bf 07 00 00 00 44 89 fe e8 e1 30 12 00 41 83 ff 07 0f 87 5c 01 00 00 e8 92 2c 12 00 45 89 fd <41> c1 ef 06 4a 8d 3c fd 70 ee 7c 8f be 08 00 00 00 e8 a9 f0 77 00
RSP: 0018:ffffc90000007d08 EFLAGS: 00000006
RAX: ffffffff81add72e RBX: ffff88807ed18340 RCX: ffff88805698bc80
RDX: 0000000000010000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 0000000000000000 R08: ffffffff999abfc3 R09: 1ffffffff33357f8
R10: dffffc0000000000 R11: fffffbfff33357f9 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880b8827bc0 R15: 0000000000000000
FS:  00007f0fbf28a6c0(0000) GS:ffff88812613b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30b1cff8 CR3: 000000005d37a000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 __run_hrtimer kernel/time/hrtimer.c:1794 [inline]
 __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 5b ab 7e f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 83 d9 46 f6 65 8b 05 dc 38 25 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc9000d6e7a20 EFLAGS: 00000206
RAX: 5f4f6390c3cf7300 RBX: 0000000000000216 RCX: 5f4f6390c3cf7300
RDX: 0000000000000007 RSI: ffffffff8d70e436 RDI: 0000000000000001
RBP: ffffc9000d6e7ab0 R08: ffffffff8f7cee77 R09: 1ffffffff1ef9dce
R10: dffffc0000000000 R11: fffffbfff1ef9dcf R12: dffffc0000000000
R13: ffff8880b8827ac0 R14: ffff8880b8827ac0 R15: 1ffff92001adcf44
 clock_was_set+0x63b/0x7c0 kernel/time/hrtimer.c:965
 do_adjtimex+0x228/0x310 kernel/time/timekeeping.c:2753
 do_clock_adjtime kernel/time/posix-timers.c:1161 [inline]
 __do_sys_clock_adjtime kernel/time/posix-timers.c:1173 [inline]
 __se_sys_clock_adjtime kernel/time/posix-timers.c:1164 [inline]
 __x64_sys_clock_adjtime+0x211/0x2c0 kernel/time/posix-timers.c:1164
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0fbe38f749
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:00007f0fbf28a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131
RAX: ffffffffffffffda RBX: 00007f0fbe5e5fa0 RCX: 00007f0fbe38f749
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000000
RBP: 00007f0fbe413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0fbe5e6038 R14: 00007f0fbe5e5fa0 R15: 00007ffeb164dce8
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g52433 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:27224 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 5e c3 c9 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 93 b1 21 00 f3 0f 1e fa fb f4 <e9> 33 c3 c9 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: fafedf71b9d44800 RBX: ffffffff81967b47 RCX: fafedf71b9d44800
RDX: 0000000000000001 RSI: ffffffff8d70e436 RDI: ffffffff8bbf08e0
RBP: ffffc90000197f10 R08: ffff8880b8932fdb R09: 1ffff110171265fb
R10: dffffc0000000000 R11: ffffed10171265fc R12: ffffffff8f7cee70
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110038d9b58
FS:  0000000000000000(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000001c000 CR3: 0000000030f04000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x1e7/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>