rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P154/1:b..l
	(detected by 1, t=10502 jiffies, g=10385, q=304)
task:kworker/u4:2    state:R  running task     stack:20928 pid:  154 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:debug_lockdep_rcu_enabled+0x9/0x30 kernel/rcu/update.c:280
Code: c0 16 0b 8a 48 c7 c6 40 3b 0b 8a e8 c1 33 f5 ff 0f 0b eb d1 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 31 c0 83 3d 7b 62 c0 03 00 <74> 1d 83 3d f2 94 c0 03 00 74 14 65 48 8b 0d 64 3b 59 76 31 c0 83
RSP: 0018:ffffc90001fd7b70 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff897edbd0 RCX: ffff88801bc5bb80
RDX: 0000000000000000 RSI: ffffffff8a59a4a0 RDI: ffffffff8a59a460
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1ff7a19
R10: fffffbfff1ff7a19 R11: 1ffffffff1ff7a18 R12: ffff88802c5dc8d0
R13: 0000000000000000 R14: ffff88802c5dc8c0 R15: ffff888022ee0c80
 rcu_read_unlock include/linux/rcupdate.h:768 [inline]
 batadv_nc_process_nc_paths+0x227/0x350 net/batman-adv/network-coding.c:703
 batadv_nc_worker+0x3e5/0x5c0 net/batman-adv/network-coding.c:732
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10526 jiffies! g10385 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=5414
rcu: rcu_preempt kthread starved for 10527 jiffies! g10385 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:27584 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 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 1
CPU: 1 PID: 4602 Comm: syz.1.79 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 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:__task_pid_nr_ns+0x1/0x420 kernel/pid.c:494
Code: 6d 6d 00 e9 1f ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 7c 91 48 89 df e8 fd 6c 6d 00 eb 87 66 2e 0f 1f 84 00 00 00 00 00 90 55 <41> 57 41 56 41 55 41 54 53 48 89 d3 89 f5 49 89 fe e8 d9 04 29 00
RSP: 0018:ffffc9000340ff08 EFLAGS: 00000246
RAX: ffffffff814c1d35 RBX: ffffc9000340ff20 RCX: ffff888024c29dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888024c29dc0
RBP: ffffc9000340ff48 R08: dffffc0000000000 R09: fffffbfff1ad32b6
R10: fffffbfff1ad32b6 R11: 1ffffffff1ad32b5 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc9000340ff58 R15: 0000000000000027
 task_tgid_vnr include/linux/sched.h:1585 [inline]
 __ia32_sys_getpid+0x19/0x20 kernel/sys.c:945
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc0d6636e67
Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d 32 6a d9 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 13 f8 fb ff 0f 1f 00 b8 27 00 00 00 0f 05 <c3> 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007fff3cb70ac8 EFLAGS: 00000202 ORIG_RAX: 0000000000000027
RAX: ffffffffffffffda RBX: 00007fff3cb70c30 RCX: 00007fc0d6636e67
RDX: 00007fff3cb70b00 RSI: 00007fff3cb70c30 RDI: 0000000000000021
RBP: 0000000000000000 R08: 0035ea1bfdb7494e R09: 000000183cb7139f
R10: 00007fff3cb711a0 R11: 0000000000000202 R12: 00007fc0d689718c
R13: 00007fff3cb711a0 R14: 000000000001dc68 R15: 00007fff3cb711c0
 </TASK>