rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=dabc/1/0x4000000000000000 softirq=20189/20190 fqs=0
rcu: (detected by 0, t=10504 jiffies, g=13965, q=1069 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6481 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rcu_is_watching+0x74/0xb0 kernel/rcu/tree.c:753
Code: 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d d9 5f fa 10 74 11 83 e0 04 c1 e8 02 5b 41 5e 41 5f <c3> cc cc cc cc cc e8 c1 66 8d ff eb e8 48 c7 c7 00 fc 13 8e 48 89
RSP: 0018:ffffc90000a08d10 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 7687290d8a28ee00
RDX: ffff88802a415a00 RSI: ffffffff8be33860 RDI: ffffffff8be33820
RBP: ffffc90000a08e90 R08: ffffffff8fa39237 R09: 1ffffffff1f47246
R10: dffffc0000000000 R11: fffffbfff1f47247 R12: ffff88807873c340
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b8727c00
FS: 0000555574d55500(0000) GS:ffff888125d14000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1d21fb6980 CR3: 00000000622b2000 CR4: 00000000003526f0
Call Trace:
<IRQ>
trace_hrtimer_cancel include/trace/events/timer.h:317 [inline]
debug_deactivate+0x80/0x200 kernel/time/hrtimer.c:491
__run_hrtimer kernel/time/hrtimer.c:1729 [inline]
__hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 7b 61 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90019527bd8 EFLAGS: 00000206
RAX: 7687290d8a28ee00 RBX: 0000000000000000 RCX: 7687290d8a28ee00
RDX: 0000000000000000 RSI: ffffffff8dba9235 RDI: ffffffff8be33880
RBP: ffffffff82339cd1 R08: 0000000000000000 R09: ffffffff82339cd1
R10: 0000000006000000 R11: 0000000000000000 R12: 0000000000000001
R13: ffff88807bb52428 R14: 0000000000000001 R15: 0000000000000246
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs.h:1798 [inline]
sb_start_write+0x4d/0x1c0 include/linux/fs.h:1934
file_start_write include/linux/fs.h:3107 [inline]
vfs_write+0x211/0xb30 fs/read_write.c:682
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1d21f8d69f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007ffe6ddffe80 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f1d21f8d69f
RDX: 0000000000000004 RSI: 00007ffe6ddffed0 RDI: 0000000000000003
RBP: 00007f1d220136a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00007ffe6ddffed0 R14: 000000000001afdc R15: 00007ffe6de00440
</TASK>
rcu: rcu_preempt kthread starved for 10504 jiffies! g13965 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
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+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 06 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 b1 5e 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 95 5e 0b 00 eb e4 44
RSP: 0018:ffffc90000117660 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110170e7f61 RCX: ffff88801ce95a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900001177e0 R08: ffffffff8fa39237 R09: 1ffffffff1f47246
R10: dffffc0000000000 R11: fffffbfff1f47247 R12: ffff8880b873fb08
R13: dffffc0000000000 R14: ffff8880b863b1c0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125c14000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f50767e9d58 CR3: 000000000df36000 CR4: 00000000003526f0
Call Trace:
<TASK>
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2653 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>