rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6265/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=89585, q=167 ncpus=2)
task:kworker/u4:11   state:R  running task     stack:20232 pid:6265  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 preempt_schedule_irq+0xbf/0x150 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+0x208/0x420 kernel/locking/lockdep.c:5758
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 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 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc9000bfcfa40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 6d95836347b28b00
RDX: 0000000000000000 RSI: ffffffff8acadb60 RDI: ffffffff8b1c89a0
RBP: ffffc9000bfcfb48 R08: dffffc0000000000 R09: 1ffffffff22386a0
R10: dffffc0000000000 R11: fffffbfff22386a1 R12: 1ffff920017f9f54
R13: ffffffff8d1320a0 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: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
 </TASK>
rcu: rcu_preempt kthread starved for 10527 jiffies! g89585 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:26728 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 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
 </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: 14774 Comm: syz.7.2092 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
Code: 89 c4 48 89 e7 e8 06 ea e5 ff e9 a1 04 00 00 90 f3 0f 1e fa 0f 01 ca fc 6a ff e8 a1 03 00 00 48 89 c4 48 89 e7 e8 56 e8 e5 ff <e9> 81 04 00 00 90 f3 0f 1e fa 0f 01 ca fc 6a ff e8 81 03 00 00 48
RSP: 0018:ffffc90004cffbc8 EFLAGS: 00000082
RAX: bd64c7e6436dba00 RBX: 0000000000000000 RCX: bd64c7e6436dba00
RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c89a0
RBP: 0000000000000000 R08: ffffffff8e8b02af R09: 1ffffffff1d16055
R10: dffffc0000000000 R11: fffffbfff1d16056 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fe99f9a06c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000004fdc7000 CR4: 00000000003506f0
Call Trace:
 <TASK>
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 5a fd d8 f6 48 89 df e8 12 d2 d9 f6 e8 dd e2 fd f6 fb bf 01 00 00 00 <e8> f2 d8 cc f6 65 8b 05 63 06 74 75 85 c0 74 02 5b c3 e8 e0 ed 70
RSP: 0018:ffffc90004cffc78 EFLAGS: 00000286
RAX: bd64c7e6436dba00 RBX: ffff8880563c5c80 RCX: bd64c7e6436dba00
RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 0000000000000001
RBP: ffff8880563c6118 R08: ffffffff8e8b02af R09: 1ffffffff1d16055
R10: dffffc0000000000 R11: fffffbfff1d16056 R12: 1ffff1100ac78c23
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x11f5/0x13f0 kernel/signal.c:2905
 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
 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: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: 0033:0x7fe99eb9c817
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:00007fe99f9a00e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007fe99ee15fa8 RCX: 00007fe99eb9c819
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe99ee15fa8
RBP: 00007fe99ee15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe99ee16038 R14: 00007ffef2960e50 R15: 00007ffef2960f38
 </TASK>