rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=34d/1/0x4000000000000000 softirq=17369/17369 fqs=3 
	(detected by 1, t=10502 jiffies, g=22449, q=169)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3057 Comm: kworker/u4:4 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:214 [inline]
RIP: 0010:rb_erase+0xf8/0xe20 lib/rbtree.c:443
Code: 00 00 fc ff df 80 3c 08 00 74 d2 48 89 ef e8 df 33 92 fd eb c8 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 be 33 92 fd 4c 8b 3b 4c 89 fd 4c 8b 6c 24 18 48
RSP: 0000:ffffc90000007cc8 EFLAGS: 00000046
RAX: 1ffff1100fb74468 RBX: ffff88807dba2340 RCX: dffffc0000000000
RDX: 0000000000010000 RSI: ffff8880b8e2a450 RDI: ffff88807dba2348
RBP: dffffc0000000000 R08: ffffffff843904b4 R09: fffffbfff1c153f6
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 1ffff1100fb7446a R14: 0000000000000000 R15: ffff88807dba2350
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3071affc CR3: 000000001f5ea000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 rb_erase_cached include/linux/rbtree.h:126 [inline]
 timerqueue_del+0xa8/0xf0 lib/timerqueue.c:57
 __remove_hrtimer kernel/time/hrtimer.c:1117 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1668 [inline]
 __hrtimer_run_queues+0x3e9/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 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:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627
Code: 2b 00 74 08 4c 89 f7 e8 0c ac 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0000:ffffc9000ce5fa80 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff920019cbf5c RCX: 1ffff920019cbefc
RDX: dffffc0000000000 RSI: ffffffff8aab3d00 RDI: ffffffff8af9fa80
RBP: ffffc9000ce5fbd8 R08: dffffc0000000000 R09: fffffbfff2131e19
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920019cbf58
R13: dffffc0000000000 R14: ffffc9000ce5fae0 R15: 0000000000000246
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0xc1/0x5b0 net/batman-adv/network-coding.c:723
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread starved for 10496 jiffies! g22449 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:27000 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375
 schedule+0x11b/0x1f0 kernel/sched/core.c:6458
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 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: 5377 Comm: kworker/1:14 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events fqdir_free_fn
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1688 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 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:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_single+0x297/0x530 kernel/smp.c:758
Code: 00 44 8b 6c 24 48 44 89 ee 83 e6 01 31 ff e8 20 ef 0b 00 41 83 e5 01 75 0a e8 b5 eb 0b 00 e9 eb 00 00 00 f3 90 42 0f b6 04 23 <84> c0 75 15 f7 44 24 48 01 00 00 00 0f 84 cd 00 00 00 e8 92 eb 0b
RSP: 0018:ffffc9000356fa60 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff920006adf55 RCX: ffff88807d903b80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000356fb50 R08: ffffffff8174b100 R09: ffffed10171c7679
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 0000000000000001 R14: ffffc9000356faa8 R15: 0000000000000000
 rcu_barrier+0x262/0x4e0 kernel/rcu/tree.c:4078
 fqdir_free_fn+0x2e/0x130 net/ipv4/inet_fragment.c:166
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
vkms_vblank_simulate: vblank timer overrun