rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4349/1:b..l
	(detected by 0, t=10502 jiffies, g=37477, q=31 ncpus=2)
task:kworker/u4:9    state:R  running task     stack:23168 pid:4349  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10e9/0x40d0 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_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:792 [inline]
RIP: 0010:batadv_nc_process_nc_paths+0xf5/0x390 net/batman-adv/network-coding.c:687
Code: 31 c0 45 31 c9 48 89 44 24 28 50 e8 55 3a 89 f7 48 83 c4 08 e8 9c 9b 35 00 41 89 c6 31 ff 89 c6 e8 b0 2b a7 f7 45 85 f6 74 10 <e8> f6 56 91 f7 84 c0 74 0e e8 3d 28 a7 f7 eb 58 e8 36 28 a7 f7 eb
RSP: 0018:ffffc9000499fb70 EFLAGS: 00000202
RAX: ffffffff89d9ab60 RBX: ffffffff89d9ae00 RCX: 0000000000000000
RDX: ffff88807ce51dc0 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff888019a96968 R08: dffffc0000000000 R09: fffffbfff2117049
R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: dffffc0000000000
R13: 1ffff1100b2b02f3 R14: 0000000000000001 R15: ffff888059580c80
 batadv_nc_worker+0x425/0x600 net/batman-adv/network-coding.c:728
 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 starved for 10527 jiffies! g37477 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:28096 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10e9/0x40d0 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:
CPU: 0 PID: 8860 Comm: syz.3.1246 Not tainted 6.1.138-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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 4e 1b 4a f7 48 89 df e8 a6 e0 4a f7 e8 11 e3 6d f7 fb bf 01 00 00 00 <e8> b6 5d 3e f7 65 8b 05 b7 22 e9 75 85 c0 74 02 5b c3 e8 04 34 e7
RSP: 0018:ffffc9000c3ffbb8 EFLAGS: 00000286
RAX: 611aa80f4335f300 RBX: ffff888077f6ef00 RCX: 611aa80f4335f300
RDX: dffffc0000000000 RSI: ffffffff8a6bfe00 RDI: 0000000000000001
RBP: ffff888077f6f198 R08: dffffc0000000000 R09: ffffed100efedde1
R10: ffffed100efedde1 R11: 1ffff1100efedde0 R12: 1ffff1100efede33
R13: 0000000000000011 R14: dffffc0000000000 R15: 0000000000000000
FS:  000055556629f500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c39b151 CR3: 0000000028651000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 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+0xb1/0x140 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: 0033:0x7f1b1a78e969
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:00007fff44bc72d8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 0000000000080741 RCX: 00007f1b1a78e969
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1b1a9b608c
RBP: 0000000000000032 R08: 000830191aa886f2 R09: 0000001644bc75cf
R10: 00007fff44bc73d0 R11: 0000000000000246 R12: 00007f1b1a9b608c
R13: 00007fff44bc73d0 R14: 0000000000080773 R15: 00007fff44bc73f0
 </TASK>