rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=f4ec/1/0x4000000000000000 softirq=20251/20273 fqs=0
rcu: (detected by 1, t=10505 jiffies, g=22537, q=629 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 495 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:rb_add_linked include/linux/rbtree.h:283 [inline]
RIP: 0010:timerqueue_linked_add+0x2c5/0x2e0 lib/timerqueue.c:96
Code: 94 c0 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 1a a6 f8 f5 48 83 c3 08 48 89 d8 48 c1 e8 03 80 3c 28 00 <74> 08 48 89 df e8 21 43 66 f6 4c 89 2b 41 80 3c 2e 00 75 b5 eb bb
RSP: 0018:ffffc90000007d58 EFLAGS: 00000046
RAX: 1ffff110170c506c RBX: ffff8880b8628360 RCX: ffff888025859f00
RDX: 0000000000010000 RSI: ffff8880b8628358 RDI: ffff88805d8ea300
RBP: dffffc0000000000 R08: ffff88805d8ea317 R09: 0000000000000000
R10: ffff88805d8ea308 R11: ffffed100bb1d463 R12: 1ffff110170c5060
R13: ffff88805d8ea300 R14: 1ffff1100bb1d463 R15: ffff88805d8ea318
FS: 0000000000000000(0000) GS:ffff888124f49000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000320f3e7e8000 CR3: 000000007c14c000 CR4: 00000000003526f0
Call Trace:
enqueue_hrtimer+0x18e/0x2c0 kernel/time/hrtimer.c:1117
__run_hrtimer kernel/time/hrtimer.c:2048 [inline]
__hrtimer_run_queues+0x4ce/0xa10 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 51 cd 2f 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 db b7 ca 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 80 d0 32 0a cc 48 8d 3d e8 65 b8
RSP: 0018:ffffc90003cef8a0 EFLAGS: 00000286
RAX: a59fa748c5dac400 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 0000000054bc367c RSI: ffffffff8e4b23ad RDI: ffffffff8c4bbf80
RBP: ffffffff8b98eba4 R08: ffffffff8b98eba4 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: 0000000000000002
R13: ffffffff8eb59c60 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:840 [inline]
batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:784 [inline]
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:862 [inline]
batadv_iv_ogm_schedule+0x485/0xff0 net/batman-adv/bat_iv_ogm.c:918
batadv_iv_send_outstanding_bat_ogm_packet+0x67a/0x790 net/batman-adv/bat_iv_ogm.c:1807
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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 10505 jiffies! g22537 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:27656 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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:
CPU: 1 UID: 0 PID: 5756 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x11f6/0x15f0 kernel/smp.c:912
Code: 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 8e 1a 0c 00 eb 37 f3 90 41 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 <74> 1e e8 73 1a 0c 00 eb e5 44 89 f1 80 e1 07 80 c1 03 38 c1 7c e3
RSP: 0018:ffffc9000371f700 EFLAGS: 00000202
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff88802c421f00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000371f860 R08: ffffffff90578f37 R09: 1ffffffff20af1e6
R10: dffffc0000000000 R11: fffffbfff20af1e7 R12: 1ffff110170c85fd
R13: ffff8880b873c448 R14: ffff8880b8642fe8 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125049000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055eac4c0fa38 CR3: 000000000e946000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1077
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
smp_text_poke_batch_finish+0x5fd/0x1110 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:911
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245