rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P2970/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=17885, q=546 ncpus=2)
task:kworker/u4:8    state:R  running task     stack:24776 pid:2970  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7010
 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:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc9000b8c7a40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: e7d995c5c05ed500
RDX: 0000000000000000 RSI: ffffffff8aaacbc0 RDI: ffffffff8afc6780
RBP: ffffc9000b8c7b48 R08: dffffc0000000000 R09: 1ffffffff21b46a4
R10: dffffc0000000000 R11: fffffbfff21b46a5 R12: 1ffff92001718f54
R13: ffffffff8cd2fba0 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 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
 </TASK>
rcu: rcu_preempt kthread starved for 10530 jiffies! g17885 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27528 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 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
 </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: 6360 Comm: syz.6.25 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lock_is_held_type+0x13e/0x190 kernel/locking/lockdep.c:5830
Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc900046afb38 EFLAGS: 00000206
RAX: 5a6c1fce70123c00 RBX: ffff888023d11e00 RCX: 5a6c1fce70123c00
RDX: 0000000000000000 RSI: ffffffff8aaacbc0 RDI: ffffffff8afc6780
RBP: 0000000000000000 R08: ffff888023d11e07 R09: 1ffff110047a23c0
R10: dffffc0000000000 R11: ffffed10047a23c1 R12: ffff888023d11e00
R13: 0000000000000246 R14: ffffffff8cd2fc00 R15: 00000000ffffffff
FS:  0000555566225500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000005afd8000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 lock_is_held include/linux/lockdep.h:288 [inline]
 __might_resched+0xa7/0x610 kernel/sched/core.c:10171
 try_to_freeze include/linux/freezer.h:53 [inline]
 get_signal+0x12e/0x1400 kernel/signal.c:2691
 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 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+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff10db8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffeb2c318a8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007ff10ddb5fa8 RCX: 00007ff10db8ebe9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007ff10ddb5fac
RBP: 0000000000000000 R08: 0000000000745aed R09: 00000004b2c31b9f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff10ddb5fac
R13: 00007ff10ddb5fa0 R14: 0000000000001d9e R15: 0000000000000004
 </TASK>