rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=a804/1/0x4000000000000000 softirq=113913/113914 fqs=1
rcu: 	(detected by 1, t=10503 jiffies, g=113521, q=1126 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12013 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: bat_events batadv_tt_purge
RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
RIP: 0010:do_raw_spin_lock+0x6c/0x2f0 kernel/locking/spinlock_debug.c:115
Code: 24 28 15 66 14 8e 48 c7 44 24 30 80 56 a2 81 4c 8d 64 24 20 49 c1 ec 03 48 b8 f1 f1 f1 f1 f8 f3 f3 f3 49 89 04 14 4c 8d 77 04 <4c> 89 f0 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 f3 01 00 00 41 8b 06
RSP: 0018:ffffc90000007ca0 EFLAGS: 00000802
RAX: f3f3f3f8f1f1f1f1 RBX: ffffffff9a705a78 RCX: 0000000000010203
RDX: dffffc0000000000 RSI: ffffffff8e21a139 RDI: ffffffff9a705a78
RBP: ffffc90000007d58 R08: ffffffff84bca6dc R09: ffffffff9a705a90
R10: ffff888027859308 R11: ffffed1004f0b263 R12: 1ffff92000000f98
R13: ffffffff9a705a70 R14: ffffffff9a705a7c R15: ffff888027859300
FS:  0000000000000000(0000) GS:ffff88812528a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055833111ca38 CR3: 000000000e74a000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock_irqsave+0x4c/0x60 kernel/locking/spinlock.c:166
 debug_object_deactivate+0x6c/0x3a0 lib/debugobjects.c:890
 debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1898 [inline]
 __hrtimer_run_queues+0x23a/0xa20 kernel/time/hrtimer.c:1994
 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:check_region_inline mm/kasan/generic.c:185 [inline]
RIP: 0010:kasan_check_range+0x19/0x2c0 mm/kasan/generic.c:200
Code: cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 41 57 41 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 ae 01 00 00 <4c> 8d 04 37 49 39 f8 0f 82 36 02 00 00 49 b9 00 00 00 00 00 80 ff
RSP: 0018:ffffc900068df8c8 EFLAGS: 00000202
RAX: 00000000ffffff01 RBX: ffff888060315840 RCX: ffffffff81a2579c
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888060315840
RBP: ffffc900068df9b8 R08: ffffffff8b7757aa R09: ffff888060315858
R10: dffffc0000000000 R11: fffffbfff206179f R12: 1ffff92000d1bf24
R13: ffff888060315848 R14: dffffc0000000000 R15: 1ffff1100c062b09
 instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
 do_raw_spin_lock+0x11c/0x2f0 kernel/locking/spinlock_debug.c:116
 spin_lock_bh include/linux/spinlock.h:348 [inline]
 batadv_tt_local_purge+0x10a/0x340 net/batman-adv/translation-table.c:1318
 batadv_tt_purge+0x35/0x9e0 net/batman-adv/translation-table.c:3514
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread starved for 10498 jiffies! g113521 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27544 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 10106 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfcf/0x13d0 kernel/smp.c:892
Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 7a 06 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 25 02 0c 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 0a 02 0c
RSP: 0018:ffffc9000e236220 EFLAGS: 00000293
RAX: ffffffff81b9c256 RBX: ffff8880b873c148 RCX: ffff888078839ec0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000e236350 R08: ffff88803c4e8b87 R09: 1ffff1100789d170
R10: dffffc0000000000 R11: ffffffff8178e300 R12: 1ffff110170c8589
R13: dffffc0000000000 R14: ffff8880b8642c48 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88812538a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc98fa12060 CR3: 000000007f28a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x5c3/0x10b0 arch/x86/mm/tlb.c:1451
 flush_tlb_page arch/x86/include/asm/tlbflush.h:345 [inline]
 ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:104
 page_vma_mkclean_one+0x438/0x780 mm/rmap.c:1138
 page_mkclean_one+0x1d8/0x2b0 mm/rmap.c:1186
 __rmap_walk_file+0x467/0x620 mm/rmap.c:3062
 rmap_walk mm/rmap.c:3106 [inline]
 folio_mkclean+0x2bb/0x3d0 mm/rmap.c:1218
 folio_clear_dirty_for_io+0x1a5/0x710 mm/page-writeback.c:2905
 mpage_submit_folio+0x86/0x2b0 fs/ext4/inode.c:2084
 mpage_process_page_bufs+0x6d5/0x8e0 fs/ext4/inode.c:2214
 mpage_prepare_extent_to_map+0xe1b/0x16f0 fs/ext4/inode.c:2753
 ext4_do_writepages+0xbac/0x4670 fs/ext4/inode.c:2894
 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3042
 do_writepages+0x32e/0x550 mm/page-writeback.c:2571
 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
 writeback_sb_inodes+0x979/0x19d0 fs/fs-writeback.c:2056
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2132
 wb_writeback+0x459/0xb00 fs/fs-writeback.c:2243
 wb_check_old_data_flush fs/fs-writeback.c:2347 [inline]
 wb_do_writeback fs/fs-writeback.c:2400 [inline]
 wb_workfn+0xb12/0xf10 fs/fs-writeback.c:2428
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>