rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=0724/1/0x4000000000000000 softirq=25764/25768 fqs=9
rcu: (detected by 1, t=10502 jiffies, g=17965, q=1324 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 1833 Comm: kworker/0:3 Not tainted 6.16.0-syzkaller-g7e161a991ea7 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events nsim_fib_event_work
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
RIP: 0010:_raw_spin_lock_irqsave+0x60/0xf0 kernel/locking/spinlock.c:162
Code: a1 8d 48 c7 44 24 10 10 1b 73 8b 49 89 e7 49 c1 ef 03 48 b8 f1 f1 f1 f1 00 f3 f3 f3 49 bc 00 00 00 00 00 fc ff df 4b 89 04 27 <48> c7 44 24 20 00 00 00 00 9c 8f 44 24 20 4c 8b 74 24 20 fa 41 f7
RSP: 0018:ffffc90000007c00 EFLAGS: 00000802
RAX: f3f3f300f1f1f1f1 RBX: ffffffff99c98728 RCX: 0000000000009ca0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff99c98728
RBP: ffffc90000007c98 R08: ffffc90000007cbf R09: 0000000000000000
R10: ffffc90000007cb0 R11: fffff52000000f98 R12: dffffc0000000000
R13: dffffc0000000000 R14: 1a3fb42ff4000000 R15: 1ffff92000000f80
FS: 0000000000000000(0000) GS:ffff888125c5c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c007c59000 CR3: 0000000029538000 CR4: 00000000003526f0
Call Trace:
debug_object_deactivate+0x9a/0x250 lib/debugobjects.c:873
debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline]
debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:490
__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
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5225
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 af 09 e2 09 e8 7a 3f 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900051572d8 EFLAGS: 00000286
RAX: 53f369503bad6a00 RBX: 0000000000000000 RCX: 53f369503bad6a00
RDX: 0000000000000006 RSI: ffffffff8d99eec8 RDI: ffffffff8be23e00
RBP: ffffc90005157330 R08: ffffffff8fa20437 R09: 1ffffffff1f44086
R10: dffffc0000000000 R11: fffffbfff1f44087 R12: ffff888028901e00
R13: dffffc0000000000 R14: ffff88802ea40000 R15: ffff8880b863a9d8
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x174a/0x4c70 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
schedule_timeout_uninterruptible kernel/time/sleep_timeout.c:158 [inline]
msleep+0xa2/0x100 kernel/time/sleep_timeout.c:318
nsim_fib6_rt_add drivers/net/netdevsim/fib.c:693 [inline]
nsim_fib6_rt_insert drivers/net/netdevsim/fib.c:759 [inline]
nsim_fib6_event drivers/net/netdevsim/fib.c:856 [inline]
nsim_fib_event drivers/net/netdevsim/fib.c:889 [inline]
nsim_fib_event_work+0x269f/0x3180 drivers/net/netdevsim/fib.c:1493
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+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 10484 jiffies! g17965 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:26792 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1742/0x4c70 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+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted 6.16.0-syzkaller-g7e161a991ea7 #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+0xd33/0x12d0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 a6 62 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 51 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 35 5e
RSP: 0018:ffffc90000117660 EFLAGS: 00000293
RAX: ffffffff81b44b7b RBX: 1ffff110170c8319 RCX: ffff88801ce9da00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900001177e0 R08: ffffffff8fa20437 R09: 1ffffffff1f44086
R10: dffffc0000000000 R11: fffffbfff1f44087 R12: ffff8880b86418c8
R13: dffffc0000000000 R14: ffff8880b873b040 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125d5c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd10329ed9 CR3: 000000000df36000 CR4: 00000000003526f0
Call Trace:
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:2654 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2864
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+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245