rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P154/1:b..l P3546/1:b..l
	(detected by 0, t=10502 jiffies, g=24285, q=59)
task:udevd           state:R  running task     stack:23168 pid: 3546 ppid:     1 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 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 9c 9e 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: 0018:ffffc90002ebf700 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff920005d7eec RCX: 1ffff920005d7e8c
RDX: dffffc0000000000 RSI: ffffffff8aab3e20 RDI: ffffffff8af9f2c0
RBP: ffffc90002ebf860 R08: dffffc0000000000 R09: fffffbfff2131821
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920005d7ee8
R13: dffffc0000000000 R14: ffffc90002ebf760 R15: 0000000000000246
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 is_bpf_text_address+0x1d/0x260 kernel/bpf/core.c:725
 kernel_text_address kernel/extable.c:151 [inline]
 __kernel_text_address+0x94/0x100 kernel/extable.c:105
 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
 arch_stack_walk+0xf3/0x140 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kmem_cache_free+0x91/0x1f0 mm/slub.c:3515
 putname fs/namei.c:271 [inline]
 user_path_at_empty+0x12b/0x180 fs/namei.c:2885
 do_readlinkat+0x114/0x3a0 fs/stat.c:442
 __do_sys_readlink fs/stat.c:475 [inline]
 __se_sys_readlink fs/stat.c:472 [inline]
 __x64_sys_readlink+0x7b/0x90 fs/stat.c:472
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe167211d47
RSP: 002b:00007ffdedcbaf28 EFLAGS: 00000246 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffdedcbaf38 RCX: 00007fe167211d47
RDX: 0000000000000400 RSI: 00007ffdedcbaf38 RDI: 00007ffdedcbb418
RBP: 0000000000000400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000812 R11: 0000000000000246 R12: 00007ffdedcbb418
R13: 00007ffdedcbb388 R14: 000055deb0204910 R15: 0000000000000000
 </TASK>
task:kworker/u4:2    state:R  running task     stack:20984 pid:  154 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:740 [inline]
RIP: 0010:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
RIP: 0010:batadv_nc_worker+0xd1/0x5b0 net/batman-adv/network-coding.c:723
Code: e8 b4 47 ae f7 4a 8d 1c e5 00 00 00 00 49 03 1f e8 04 c5 4f f7 e8 8f 81 00 00 e8 aa 2e 23 00 89 c5 31 ff 89 c6 e8 8f 62 64 f7 <85> ed 74 10 e8 16 13 4f f7 84 c0 74 0e e8 1d 5f 64 f7 eb 56 e8 16
RSP: 0018:ffffc90001fc7bf8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff888078bccc00 RCX: ffff88801e149dc0
RDX: ffff88801e149dc0 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff8a1c2661 R09: fffffbfff2131821
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000180
R13: dffffc0000000000 R14: ffff888074ce0c80 R15: ffff888059bb9740
 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 10558 jiffies! g24285 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:27256 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562