rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-....: (1 GPs behind) idle=f78c/1/0x4000000000000000 softirq=23348/23350 fqs=2701
rcu: hardirqs softirqs csw/system
rcu: number: 1432942 0 0
rcu: cputime: 17465 35024 38 ==> 52520(ms)
rcu: (t=10504 jiffies g=29705 q=725 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 5068 jiffies! g29705 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=20778
rcu: rcu_preempt kthread starved for 5071 jiffies! g29705 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27112 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:queued_write_lock_slowpath+0x137/0x2ac kernel/locking/qrwlock.c:85
Code: f0 41 81 0e 00 01 00 00 42 0f b6 04 23 84 c0 74 37 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 2a 4c 89 f7 e8 1d 1f 4f f7 eb 20 f3 90 <42> 0f b6 04 23 84 c0 74 15 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 08
RSP: 0018:ffffc900000e79c0 EFLAGS: 00000206
RAX: 00000000000001ff RBX: 1ffff11003dd1005 RCX: ffffffff8a9039cd
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88801ee88028
RBP: ffffc900000e7a70 R08: ffff88801ee8802b R09: 1ffff11003dd1005
R10: dffffc0000000000 R11: ffffed1003dd1006 R12: dffffc0000000000
R13: 1ffff9200001cf3c R14: ffff88801ee88028 R15: ffffc900000e7a10
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005606645c0c70 CR3: 000000000cf32000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
queued_write_lock include/asm-generic/qrwlock.h:101 [inline]
do_raw_write_lock+0x1ea/0x260 kernel/locking/spinlock_debug.c:210
neigh_periodic_work+0x466/0xd70 net/core/neighbour.c:988
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
CPU: 1 PID: 8745 Comm: syz.0.1095 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:220 [inline]
RIP: 0010:unwind_next_frame+0x27e/0x2970 arch/x86/kernel/unwind_orc.c:494
Code: 85 00 73 b2 8f 48 89 e8 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 d8 21 00 00 8b 6d 00 ff c5 4b 8d 44 6d 00 48 8d 84 00 b0 b8 08 8f <48> 89 44 24 30 48 3d 00 73 b2 8f 0f 83 f4 1c 00 00 48 8d 44 6d 00
RSP: 0018:ffffc900001f0598 EFLAGS: 00000206
RAX: ffffffff8fab7fb2 RBX: dffffc0000000000 RCX: 0000000000000100
RDX: ffff888029048000 RSI: 0000000000098662 RDI: 000000000009c000
RBP: 00000000001b2139 R08: ffffc900001f0730 R09: 000000000000000d
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001f0668
R13: 00000000001b212b R14: ffffc900001f069d R15: 0000000000098662
FS: 00007f9883e106c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9883defd58 CR3: 0000000075653000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x270 mm/slub.c:3852
__skb_queue_purge_reason include/linux/skbuff.h:3245 [inline]
__skb_queue_purge include/linux/skbuff.h:3250 [inline]
neigh_invalidate+0x394/0x450 net/core/neighbour.c:1067
neigh_timer_handler+0x914/0xff0 net/core/neighbour.c:1151
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x542/0x800 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:preempt_schedule_irq+0xba/0x150 kernel/sched/core.c:7010
Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 6f bf 01 00 00 00 e8 51 d6 cd f6 e8 7c e3 fe f6 fb bf 01 00 00 00 f1 b4 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc9001a147d60 EFLAGS: 00000286
RAX: 099e6708547ea700 RBX: 0000000000000000 RCX: 099e6708547ea700
RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 0000000000000001
RBP: ffffc9001a147e10 R08: ffffffff8e8b19af R09: 1ffffffff1d16335
R10: dffffc0000000000 R11: fffffbfff1d16336 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92003428fac
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:exit_to_user_mode_loop+0x40/0x110 kernel/entry/common.c:164
Code: fb eb 1d e8 d2 a6 12 09 65 48 8b 05 ba dc 8f 7e 4c 8b 30 41 f7 c6 0e 30 02 00 0f 84 c4 00 00 00 e8 f5 ba 19 00 fb 41 f6 c6 08 <74> 05 e8 09 d2 1a 09 41 f7 c6 00 10 00 00 74 08 48 89 df e8 78 a0
RSP: 0018:ffffc9001a147ed0 EFLAGS: 00000246
RAX: 099e6708547ea700 RBX: ffffc9001a147f58 RCX: 099e6708547ea700
RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8fa0
RBP: ffffc9001a147f48 R08: ffffffff8e8b19af R09: 1ffffffff1d16335
R10: dffffc0000000000 R11: fffffbfff1d16336 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000004002 R15: ffff888029048000
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9882f9cdd9
Code: 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 01 48
RSP: 002b:00007f9883e10028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: 0000000000000006 RBX: 00007f9883215fa0 RCX: 00007f9882f9cdd9
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007f9883032d69 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9883216038 R14: 00007f9883215fa0 R15: 00007ffc8743d968