syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4304/1:b..l
	(detected by 0, t=10502 jiffies, g=40401, q=174 ncpus=2)
task:kworker/u4:6    state:R  running task     stack:22328 pid:4304  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__rcu_read_unlock+0x3/0x100 kernel/rcu/tree_plugin.h:419
Code: 00 eb b1 44 89 f9 80 e1 07 80 c1 03 38 c1 7c b0 4c 89 ff e8 7f c9 6d 00 eb a6 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 41 57 <41> 56 41 55 41 54 53 49 bc 00 00 00 00 00 fc ff df 65 4c 8b 35 74
RSP: 0018:ffffc900045afa48 EFLAGS: 00000293
RAX: ffffffff8a72ecd2 RBX: 0000000000000001 RCX: ffff888025190000
RDX: 0000000000000000 RSI: ffffffff8b5d7520 RDI: ffffffff8b5d74e0
RBP: ffffc900045afb98 R08: ffffffff8a72ecc0 R09: fffffbfff224604d
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88805c254000
R13: ffff88805d1a4200 R14: dffffc0000000000 R15: ffff88805d269e10
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:772 [inline]
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:826 [inline]
 batadv_iv_ogm_schedule+0x6e3/0x1090 net/batman-adv/bat_iv_ogm.c:869
 batadv_iv_send_outstanding_bat_ogm_packet+0x6fa/0x800 net/batman-adv/bat_iv_ogm.c:1713
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: rcu_preempt kthread starved for 9921 jiffies! g40401 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:26712 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 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: 0 Comm: swapper/0 Not tainted 6.1.115-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline]
RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567
Code: 09 d9 f6 48 83 e3 08 0f 85 0b 01 00 00 4c 8d 74 24 20 e8 c4 c5 df f6 0f 1f 44 00 00 e8 3a 05 d9 f6 0f 00 2d 23 16 b6 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 7b 88 30 f7
RSP: 0018:ffffffff8d007b20 EFLAGS: 000002d3
RAX: ffffffff8ab18e16 RBX: 0000000000000000 RCX: ffffffff8d0bd800
RDX: 0000000000000000 RSI: ffffffff8b0c02c0 RDI: ffffffff8b5d7540
RBP: ffffffff8d007bb0 R08: ffffffff8ab18df8 R09: fffffbfff1a17b01
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1a00f64
R13: ffff8880206be804 R14: ffffffff8d007b40 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563c5d01bdb8 CR3: 000000007e12b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:704
 cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239
 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356
 call_cpuidle kernel/sched/idle.c:155 [inline]
 cpuidle_idle_call kernel/sched/idle.c:236 [inline]
 do_idle+0x3ce/0x680 kernel/sched/idle.c:303
 cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401
 rest_init+0x2da/0x300 init/main.c:733
 arch_call_rest_init+0xa/0xa init/main.c:893
 start_kernel+0x496/0x53f init/main.c:1140
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>