rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P15/5:b..l P3238/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=11013, q=1598 ncpus=2)
task:kworker/R-bat_e state:D stack:21912 pid:3238  tgid:3238  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5526 [inline]
 __schedule+0x16d9/0x5700 kernel/sched/core.c:7276
 __schedule_loop kernel/sched/core.c:7353 [inline]
 schedule_rtlock+0x30/0x70 kernel/sched/core.c:7432
 rtlock_slowlock_locked+0x35c9/0x3c20 kernel/locking/rtmutex.c:1895
 rtlock_slowlock kernel/locking/rtmutex.c:1922 [inline]
 rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
 __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
 rt_spin_lock+0x165/0x400 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:45 [inline]
 tasklet_lock_callback kernel/softirq.c:900 [inline]
 tasklet_action_common+0xc5/0x600 kernel/softirq.c:950
 handle_softirqs+0x1da/0x6d0 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 __local_bh_enable_ip+0x16f/0x2b0 kernel/softirq.c:325
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 spin_unlock_bh include/linux/spinlock_rt.h:122 [inline]
 batadv_iv_ogm_queue_add+0x7e8/0xd80 net/batman-adv/bat_iv_ogm.c:760
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:957 [inline]
 batadv_iv_ogm_schedule+0x835/0xf90 net/batman-adv/bat_iv_ogm.c:1011
 batadv_iv_send_outstanding_bat_ogm_packet+0x622/0x740 net/batman-adv/bat_iv_ogm.c:1924
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 rescuer_thread+0x7c5/0x10e0 kernel/workqueue.c:3703
 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>
task:ksoftirqd/0     state:R  running task     stack:22488 pid:15    tgid:15    ppid:2      task_flags:0x4208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5526 [inline]
 __schedule+0x16d9/0x5700 kernel/sched/core.c:7276
 preempt_schedule_notrace+0x56/0x90 kernel/sched/core.c:7548
 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_acquire+0x271/0x2e0 include/trace/events/lock.h:23
 __do_trace_lock_acquire include/trace/events/lock.h:23 [inline]
 trace_lock_acquire include/trace/events/lock.h:23 [inline]
 lock_acquire+0x303/0x350 kernel/locking/lockdep.c:5905
 rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 rcu_read_lock include/linux/rcupdate.h:849 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6499 [inline]
 kfree+0x1c5/0x6d0 mm/slub.c:6792
 ieee80211_inform_bss+0xbda/0x10d0 net/mac80211/scan.c:164
 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline]
 cfg80211_inform_single_bss_data+0xd98/0x1bf0 net/wireless/scan.c:2410
 cfg80211_inform_bss_data+0x263/0x3cc0 net/wireless/scan.c:3266
 cfg80211_inform_bss_frame_data+0x3c7/0x840 net/wireless/scan.c:3358
 ieee80211_bss_info_update+0x791/0xa50 net/mac80211/scan.c:230
 ieee80211_scan_rx+0x552/0xa40 net/mac80211/scan.c:364
 __ieee80211_rx_handle_packet net/mac80211/rx.c:5427 [inline]
 ieee80211_rx_list+0x2d23/0x3b40 net/mac80211/rx.c:5720
 ieee80211_rx_napi+0x1ad/0x3d0 net/mac80211/rx.c:5743
 ieee80211_rx include/net/mac80211.h:5449 [inline]
 ieee80211_handle_queued_frames+0xe4/0x1d0 net/mac80211/main.c:452
 tasklet_action_common+0x31c/0x600 kernel/softirq.c:961
 handle_softirqs+0x1da/0x6d0 kernel/softirq.c:645
 run_ksoftirqd+0x53/0x190 kernel/softirq.c:1099
 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
 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>