rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10506 jiffies, g=89381, q=252 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295022988-4295012486), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g89381 f0x2 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 21802 Comm: syz.4.5548 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:222 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:233 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [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_expire_exit include/trace/events/timer.h:306 [inline]
RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1780 [inline]
RIP: 0010:__hrtimer_run_queues+0x590/0xc60 kernel/time/hrtimer.c:1841
Code: 12 00 41 83 fd 07 0f 87 98 01 00 00 e8 39 5b 12 00 45 89 ef 41 c1 ed 06 4a 8d 3c ed 70 eb 7c 8f be 08 00 00 00 e8 30 20 78 00 <31> f6 4c 0f a3 3d 76 42 cf 0d 41 0f 92 c7 40 0f 92 c6 bf 02 00 00
RSP: 0018:ffffc90000a08d40 EFLAGS: 00000056
RAX: ffffffff81ada801 RBX: ffff8880b8927d08 RCX: ffffffff81ada8f0
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8f7ceb70
RBP: ffffc90000a08e90 R08: ffffffff8f7ceb77 R09: 1ffffffff1ef9d6e
R10: dffffc0000000000 R11: fffffbfff1ef9d6f R12: ffff88802f454340
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001
FS:  00007f6bd894d6c0(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6bd894cf98 CR3: 0000000077856000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 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 ab bb 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 e9 46 f6 65 8b 05 dc 48 25 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc9000e8979c0 EFLAGS: 00000206
RAX: 51c1103fe8171500 RBX: 0000000000000212 RCX: 51c1103fe8171500
RDX: 0000000000000000 RSI: ffffffff8d70e2b0 RDI: 0000000000000001
RBP: ffffc9000e897a58 R08: ffffffff8f7ceb77 R09: 1ffffffff1ef9d6e
R10: dffffc0000000000 R11: fffffbfff1ef9d6f R12: dffffc0000000000
R13: 1a558fc3e814b276 R14: ffff888054049088 R15: 1ffff92001d12f38
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 timerfd_clock_was_set+0x1ce/0x2c0 fs/timerfd.c:111
 clock_was_set+0x73b/0x7c0 kernel/time/hrtimer.c:975
 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: 0033:0x7f6bd7b8f6c9
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:00007f6bd894d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131
RAX: ffffffffffffffda RBX: 00007f6bd7de6090 RCX: 00007f6bd7b8f6c9
RDX: 0000000000000000 RSI: 0000200000000480 RDI: 0000000000000000
RBP: 00007f6bd7c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6bd7de6128 R14: 00007f6bd7de6090 R15: 00007fff40aba108
 </TASK>