rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4344/1:b..l
	(detected by 0, t=10503 jiffies, g=27709, q=94)
task:kworker/u4:10   state:R  running task     stack:20952 pid: 4344 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:40 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:75 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:107 [inline]
RIP: 0010:lock_acquire+0x193/0x4f0 kernel/locking/lockdep.c:5619
Code: 00 00 00 00 00 00 9c 8f 84 24 80 00 00 00 42 80 3c 2b 00 74 08 4c 89 ff e8 ca 9b 67 00 48 8d 5c 24 60 4c 8b bc 24 80 00 00 00 <fa> 48 c7 c7 e0 26 ab 8a e8 d0 ac dc 08 65 ff 05 d9 e1 9f 7e 45 31
RSP: 0018:ffffc900035dfa80 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc900035dfae0 RCX: ffffffff8162964c
RDX: 0000000000000000 RSI: ffffffff8af9e920 RDI: ffffffff8af9e8e0
RBP: ffffc900035dfbd8 R08: dffffc0000000000 R09: fffffbfff1c154b6
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920006bbf58
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0xc1/0x5b0 net/batman-adv/network-coding.c:723
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread starved for 10056 jiffies! g27709 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:26144 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.15.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1690 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1816
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:723
Code: 07 80 c1 03 38 c1 7c b5 4c 89 e7 e8 af 84 81 f7 eb ab e8 88 80 f6 ff 00 00 cc cc 00 00 cc cc 66 90 0f 00 2d 07 1b 5d 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffffff8c807da8 EFLAGS: 000002c2
RAX: 81fb45c9c15e1100 RBX: ffffffff8c8bd680 RCX: 0000000000161076
RDX: 0000000000000001 RSI: ffffffff8aab18e0 RDI: ffffffff8af9e940
RBP: ffffffff8c807ef8 R08: dffffc0000000000 R09: ffffed10171c765a
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1900fce
R13: 1ffffffff1917ad0 R14: 0000000000000000 R15: dffffc0000000000
 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x271/0x670 kernel/sched/idle.c:306
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
 start_kernel+0x48c/0x540 init/main.c:1140
 secondary_startup_64_no_verify+0xb1/0xbb
 </TASK>