rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P56/1:b..l
	(detected by 1, t=10502 jiffies, g=34929, q=274 ncpus=2)
task:kworker/u4:4    state:R  running task     stack:23168 pid:56    ppid:2      flags:0x00004000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:755 [inline]
RIP: 0010:batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:825 [inline]
RIP: 0010:batadv_iv_ogm_schedule+0x4a1/0xe90 net/batman-adv/bat_iv_ogm.c:868
Code: 05 14 3c 2e 04 01 48 c7 c7 40 89 ad 8b be 19 03 00 00 48 c7 c2 80 89 ad 8b e8 3b cd 86 f7 48 89 d8 48 c1 e8 03 42 80 3c 20 00 <74> 08 48 89 df e8 45 1c f4 f7 48 8b 1b 48 85 db 0f 94 c0 48 81 c3
RSP: 0018:ffffc90001577a40 EFLAGS: 00000246
RAX: 1ffff1100aa8d97c RBX: ffff88805546cbe0 RCX: ffff888019aed940
RDX: 0000000000000000 RSI: ffffffff8adefcc0 RDI: ffffffff8adefc80
RBP: ffffc90001577b80 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff888053af90a4
 batadv_iv_send_outstanding_bat_ogm_packet+0x72d/0x840 net/batman-adv/bat_iv_ogm.c:1712
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10436 jiffies! g34929 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=25251
rcu: rcu_preempt kthread starved for 10442 jiffies! g34929 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:26496 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
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: 8022 Comm: syz.0.771 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lockdep_tasklist_lock_is_held+0x0/0x20 kernel/fork.c:146
Code: 89 d3 49 89 f6 49 89 ff e8 ed cb 34 00 4c 89 ff 4c 89 f6 48 89 da 5b 41 5e 41 5f e9 aa c7 3e 00 66 2e 0f 1f 84 00 00 00 00 00 <e8> cb cb 34 00 48 c7 c7 58 a0 80 8c be ff ff ff ff e9 5a 62 cb 08
RSP: 0018:ffffc90000007c28 EFLAGS: 00000002
RAX: ffffffff8154e459 RBX: 0000000000000000 RCX: 0000000000010000
RDX: ffff88807d7ad940 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: ffff88807c8ec248
R13: ffff8880732c5140 R14: ffff88807d7adf68 R15: 0000000000000000
FS:  00007f7204e7b6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000004000 CR3: 000000002a9c0000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 pid_task+0x72/0x140 kernel/pid.c:401
 send_sigqueue+0x137/0x600 kernel/signal.c:1978
 posix_timer_event kernel/time/posix-timers.c:360 [inline]
 posix_timer_fn+0x16a/0x3d0 kernel/time/posix-timers.c:386
 __run_hrtimer kernel/time/hrtimer.c:1747 [inline]
 __hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1811
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ee f7 41 f7 48 89 df e8 46 bd 42 f7 e8 71 af 65 f7 fb bf 01 00 00 00 <e8> 96 3a 36 f7 65 8b 05 97 f3 e0 75 85 c0 74 02 5b c3 e8 e4 04 df
RSP: 0018:ffffc9000358fbb8 EFLAGS: 00000286
RAX: 39bab11a62b34600 RBX: ffff88802e572500 RCX: 39bab11a62b34600
RDX: dffffc0000000000 RSI: ffffffff8a8c0500 RDI: 0000000000000001
RBP: ffff88802e572798 R08: dffffc0000000000 R09: ffffed1005cae4a1
R10: ffffed1005cae4a1 R11: 1ffff11005cae4a0 R12: 1ffff11005cae4f3
R13: 0000000000000011 R14: dffffc0000000000 R15: 0000000000000000
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x1163/0x1350 kernel/signal.c:2874
 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7203e513f7
Code: 2f fb ff ff eb a6 b8 01 00 00 00 48 81 c4 b8 00 00 00 5b 5d 41 5c 41 5d 41 5e 41 5f c3 66 0f 1f 44 00 00 80 3d b2 69 39 00 00 <48> 8b 47 18 48 8b 4f 28 74 1f 48 8b 30 89 f2 83 c6 02 48 8d 04 f0
RSP: 002b:00007f7204e7b058 EFLAGS: 00000202
RAX: 00007f72041e6270 RBX: 00007f72041e6270 RCX: 00007f72041e6270
RDX: 00007f720409b120 RSI: 0000200000002900 RDI: 00007f72041e6308
RBP: 00007f7204011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f72041e6308 R14: 00007f72041e6270 R15: 00007ffea62d0ea8
 </TASK>