rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5462/1:b..l P8426/1:b..l
	(detected by 0, t=10502 jiffies, g=37213, q=552 ncpus=2)
task:syz.1.973       state:R  running task     stack:26256 pid:8426  ppid:4279   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6732
 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6756
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 filemap_map_pages+0xf0f/0x11e0 mm/filemap.c:3531
 do_fault_around mm/memory.c:4598 [inline]
 do_read_fault mm/memory.c:4624 [inline]
 do_fault mm/memory.c:4758 [inline]
 handle_pte_fault mm/memory.c:5029 [inline]
 __handle_mm_fault mm/memory.c:5171 [inline]
 handle_mm_fault+0x25e5/0x3d40 mm/memory.c:5292
 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338
 handle_page_fault arch/x86/mm/fault.c:1429 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f02d77eb840
RSP: 002b:00007ffcbac60c58 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007f02d7a25fa0 RCX: 0000000000000000
RDX: 00007ffcbac60c70 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f02d7a27da0 R08: 00000000000001f7 R09: 0022fe9b328c9fec
R10: 0000010770e1d2b0 R11: 00000000000182ee R12: 000000000007b17f
R13: 00007f02d7a2609c R14: 000000000007aef1 R15: 00007f02d7a26090
 </TASK>
task:kworker/u4:27   state:R  running task     stack:24880 pid:5462  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6875
 irqentry_exit+0x63/0x70 kernel/entry/common.c:442
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:lock_acquire+0x226/0x4a0 kernel/locking/lockdep.c:5794
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 ef 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc90003487a40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: bce308c1e6ea2000
RDX: 0000000000000000 RSI: ffffffff8a8c2a20 RDI: ffffffff8adf6de0
RBP: ffffc90003487b60 R08: dffffc0000000000 R09: 1ffffffff2166648
R10: dffffc0000000000 R11: fffffbfff2166649 R12: 1ffff92000690f54
R13: 0000000000000001 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 batadv_nc_process_nc_paths+0xdb/0x380 net/batman-adv/network-coding.c:687
 batadv_nc_worker+0x521/0x600 net/batman-adv/network-coding.c:735
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 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 10328 jiffies! g37213 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:26768 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 schedule+0xb9/0x180 kernel/sched/core.c:6639
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x99/0x3b0 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: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742
Code: 48 89 df e8 27 eb 95 f7 e9 44 ff ff ff e8 dd 02 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d e7 f1 48 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: 89bec88740928800 RBX: ffffffff8a3dbae7 RCX: 89bec88740928800
RDX: 0000000000000001 RSI: ffffffff8a8c18a0 RDI: ffffffff8adf6de0
RBP: ffffffff8c807ec8 R08: ffff8880b8e357cb R09: 1ffff110171c6af9
R10: dffffc0000000000 R11: ffffed10171c6afa R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff8c8bc740 R15: 1ffffffff1900fc0
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055babff25a38 CR3: 000000007e663000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 default_idle_call+0x84/0xc0 kernel/sched/idle.c:109
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x250/0x680 kernel/sched/idle.c:323
 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:422
 rest_init+0x2dc/0x300 init/main.c:706
 arch_call_rest_init+0xa/0xa init/main.c:865
 start_kernel+0x480/0x50d init/main.c:1113
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>