rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=31977, q=1342 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 256 (4294979259-4294979003), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 256 jiffies! g31977 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->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:25624 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x171d/0x56e0 kernel/sched/core.c:7382
 preempt_schedule_notrace+0x56/0x90 kernel/sched/core.c:7633
 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
 class_preempt_notrace_destructor include/linux/preempt.h:497 [inline]
 trace_event_raw_event_lock+0x241/0x280 include/trace/events/lock.h:49
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8299 Comm: kworker/u8:17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:rb_read_data_buffer+0x465/0x5b0 kernel/trace/ring_buffer.c:1970
Code: 09 c3 48 89 df 4c 89 e6 e8 48 bb fb ff 4c 39 e3 72 58 e8 3e b8 fb ff eb 36 e8 37 b8 fb ff 48 8b 44 24 08 ff c0 48 89 44 24 08 <c1> eb 05 4c 01 e3 44 01 f5 3b 6c 24 04 0f 8d b2 00 00 00 e8 13 b8
RSP: 0018:ffffc90005e97560 EFLAGS: 00000203
RAX: 0000000000000025 RBX: 000000000006b72a RCX: ffff8880326f3e80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000640 R08: ffff8880326f3e80 R09: 0000000000000020
R10: 0000000000000100 R11: 000000000000001f R12: 000000624275af75
R13: 000000000000000a R14: 000000000000002c R15: ffff888060405650
FS:  0000000000000000(0000) GS:ffff888124827000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdcd21a2492 CR3: 000000003987a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 check_buffer+0x288/0x860 kernel/trace/ring_buffer.c:4774
 __rb_reserve_next+0x549/0xdd0 kernel/trace/ring_buffer.c:4875
 rb_reserve_next_event kernel/trace/ring_buffer.c:5012 [inline]
 ring_buffer_lock_reserve+0xc0d/0x10c0 kernel/trace/ring_buffer.c:5071
 __trace_buffer_lock_reserve kernel/trace/trace.h:1674 [inline]
 trace_event_buffer_lock_reserve+0x1d4/0x700 kernel/trace/trace.c:1935
 trace_event_buffer_reserve+0x1ef/0x2d0 kernel/trace/trace_events.c:724
 do_trace_event_raw_event_lock include/trace/events/lock.h:49 [inline]
 trace_event_raw_event_lock+0x127/0x280 include/trace/events/lock.h:49
 __do_trace_lock_release include/trace/events/lock.h:68 [inline]
 trace_lock_release include/trace/events/lock.h:68 [inline]
 lock_release+0x396/0x3c0 kernel/locking/lockdep.c:5954
 rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80
 spin_unlock_bh include/linux/spinlock_rt.h:121 [inline]
 __batadv_dat_purge+0x334/0x400 net/batman-adv/distributed-arp-table.c:252
 batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:271
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/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>
sched: DL replenish lagged too much