rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6193/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=21925, q=830 ncpus=2)
task:kworker/0:4 state:R running task stack:24608 pid:6193 tgid:6193 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events nsim_fib_event_work
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x205/0xa00 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
RIP: 0010:stack_access_ok+0x28/0x1d0 arch/x86/kernel/unwind_orc.c:409
Code: 90 90 48 b8 00 00 00 00 00 fc ff df 41 55 41 54 49 89 d4 48 89 fa 55 48 c1 ea 03 48 89 f5 53 48 89 fb 48 83 ec 08 0f b6 04 02 <84> c0 74 08 3c 03 0f 8e 3f 01 00 00 8b 13 85 d2 74 65 48 b8 00 00
RSP: 0018:ffffc9000209f5e8 EFLAGS: 00000296
RAX: 0000000000000000 RBX: ffffc9000209f6d8 RCX: ffffffff91c36eba
RDX: 1ffff92000413edb RSI: ffffc9000209f768 RDI: ffffc9000209f6d8
RBP: ffffc9000209f768 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000000af71 R12: 0000000000000008
R13: ffffc9000209f6d8 R14: ffffc9000209f778 R15: ffffc9000209f70c
deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline]
unwind_next_frame+0x1551/0x2090 arch/x86/kernel/unwind_orc.c:677
__unwind_start+0x3cd/0x7e0 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2677 [inline]
slab_free mm/slub.c:6377 [inline]
kfree+0x22b/0x6c0 mm/slub.c:6692
nsim_fib_event_work+0x43a/0x6310 drivers/net/netdevsim/fib.c:1495
process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 10536 jiffies! g21925 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:27432 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
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: 6601 Comm: syz.4.69 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline]
RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline]
RIP: 0010:native_apic_msr_write arch/x86/include/asm/apic.h:208 [inline]
RIP: 0010:native_apic_msr_write+0x28/0x40 arch/x86/include/asm/apic.h:202
Code: 90 90 f3 0f 1e fa 8d 87 30 ff ff ff 83 e0 ef 74 20 89 f8 83 e0 ef 83 f8 20 74 16 c1 ef 04 31 d2 89 f0 8d 8f 00 08 00 00 0f 30 <66> 90 c3 cc cc cc cc c3 cc cc cc cc 89 f6 31 d2 89 cf e9 01 81 9d
RSP: 0018:ffffc90003bff9a8 EFLAGS: 00000046
RAX: 000000000000024d RBX: ffff8880b8523d80 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 000000000000024d RDI: 0000000000000038
RBP: 000000000000024d R08: 0000000000000005 R09: 000000000000003f
R10: 0000000000000020 R11: 0000000000000000 R12: 1ffff9200077ff41
R13: 0000000000000020 R14: 0000000000000001 R15: ffff8880b8523dc0
FS: 00007f6ec37276c0(0000) GS:ffff888123ed8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 0000000072ca4000 CR4: 00000000003526f0
Call Trace:
apic_write arch/x86/include/asm/apic.h:405 [inline]
lapic_next_event+0x10/0x20 arch/x86/kernel/apic/apic.c:418
clockevents_program_event+0x375/0x820 kernel/time/clockevents.c:372
tick_program_event+0xa9/0x140 kernel/time/tick-oneshot.c:48
hrtimer_rearm_event kernel/time/hrtimer.c:707 [inline]
__hrtimer_reprogram kernel/time/hrtimer.c:735 [inline]
__hrtimer_reprogram kernel/time/hrtimer.c:710 [inline]
hrtimer_reprogram+0x460/0x6c0 kernel/time/hrtimer.c:899
hrtimer_start_range_ns_user+0x2ba/0x4c0 kernel/time/hrtimer.c:1581
__posixtimer_deliver_signal kernel/time/posix-timers.c:317 [inline]
posixtimer_deliver_signal+0x2e3/0x6e0 kernel/time/posix-timers.c:348
dequeue_signal+0x402/0x500 kernel/signal.c:660
get_signal+0x539/0x21e0 kernel/signal.c:2926
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6ec279de97
Code: 83 c8 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
RSP: 002b:00007f6ec37270e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f6ec2a25fa8 RCX: 00007f6ec279de99
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6ec2a25fa8
RBP: 00007f6ec2a25fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6ec2a26038 R14: 00007ffe54f9a6c0 R15: 00007ffe54f9a7a8