rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P36/1:b..l P7742/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=34873, q=577 ncpus=2)
task:syz.4.463       state:R  running task     stack:25336 pid:7742  tgid:7742  ppid:7197   task_flags:0x40004c flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5282 [inline]
 __schedule+0x14db/0x5030 kernel/sched/core.c:6894
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7078
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
 _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:392 [inline]
 zap_pte_range mm/memory.c:1884 [inline]
 zap_pmd_range mm/memory.c:1946 [inline]
 zap_pud_range mm/memory.c:1975 [inline]
 zap_p4d_range mm/memory.c:1996 [inline]
 unmap_page_range+0x3c17/0x44e0 mm/memory.c:2017
 unmap_single_vma mm/memory.c:2059 [inline]
 unmap_vmas+0x399/0x580 mm/memory.c:2101
 exit_mmap+0x239/0xb10 mm/mmap.c:1277
 __mmput+0x118/0x430 kernel/fork.c:1177
 exit_mm+0x169/0x230 kernel/exit.c:581
 do_exit+0x81f/0x2590 kernel/exit.c:959
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
 __do_sys_exit_group kernel/exit.c:1123 [inline]
 __se_sys_exit_group kernel/exit.c:1121 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
 x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f813b38f749
RSP: 002b:00007ffcde4bf758 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f813b38f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffcde4bf7bc R08: 0000001ade4bf84f R09: 00000000000927c0
R10: 00000000000001d4 R11: 0000000000000246 R12: 000000000000001e
R13: 00000000000927c0 R14: 000000000004d7a3 R15: 00007ffcde4bf810
 </TASK>
task:kworker/u8:2    state:R  running task     stack:22488 pid:36    tgid:36    ppid:2      task_flags:0x4208160 flags:0x00080000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5282 [inline]
 __schedule+0x14db/0x5030 kernel/sched/core.c:6894
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221
 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 00 c6 c0 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 1a 34 04 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 ff a3 c3 09 cc 48 8d 3d d7 c3 07
RSP: 0018:ffffc90000ac7900 EFLAGS: 00000286
RAX: 02d1008631ee6500 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000f8bb1793 RSI: ffffffff8db8dbf6 RDI: ffffffff8be09d60
RBP: ffffffff8b280380 R08: ffffffff8b280380 R09: ffffffff8e144f60
R10: dffffc0000000000 R11: ffffed100ab28517 R12: 0000000000000002
R13: ffffffff8e144f60 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:761 [inline]
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:833 [inline]
 batadv_iv_ogm_schedule+0x454/0xf00 net/batman-adv/bat_iv_ogm.c:873
 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1709
 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
 process_scheduled_works kernel/workqueue.c:3362 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
 kthread+0x389/0x480 kernel/kthread.c:467
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: rcu_preempt kthread starved for 10542 jiffies! g34873 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:27656 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5282 [inline]
 __schedule+0x14db/0x5030 kernel/sched/core.c:6894
 __schedule_loop kernel/sched/core.c:6976 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6991
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297
 kthread+0x389/0x480 kernel/kthread.c:467
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </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 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 3f 29 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07dc0 EFLAGS: 000002c2
RAX: 0000000000553f21 RBX: ffffffff81977eae RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d9a99b4 RDI: ffffffff8be09d60
RBP: ffffffff8de07eb0 R08: ffff8880b863375b R09: 1ffff110170c66eb
R10: dffffc0000000000 R11: ffffed10170c66ec R12: ffffffff8fa2d8f0
R13: 1ffffffff1bd29d0 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125bf7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbdc14d87b5 CR3: 0000000076ba8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x1be/0x4d0 kernel/sched/idle.c:332
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
 rest_init+0x2de/0x300 init/main.c:758
 start_kernel+0x38b/0x3e0 init/main.c:1209
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>