rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=b36/1/0x4000000000000002 softirq=10205/10205 fqs=40 
	(t=10501 jiffies g=6389 q=109)
rcu: rcu_preempt kthread starved for 10422 jiffies! g6389 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29032    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081
 schedule+0x181/0x210 kernel/sched/core.c:4155
 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 21 Comm: kworker/u4:1 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271
 update_process_times+0x12d/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:mod_memcg_page_state+0x123/0x190 include/linux/memcontrol.h:653
Code: e8 f2 9a 69 00 48 83 3d 12 21 c2 07 00 74 70 e8 63 25 2e 00 4c 89 ff 57 9d 0f 1f 44 00 00 e8 24 c1 33 00 eb 43 e8 4d 25 2e 00 <eb> 3c e8 b6 be 33 00 48 c7 c0 28 95 0a 89 48 c1 e8 03 42 80 3c 20
RSP: 0018:ffffc90000dd79f8 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81487433 RBX: 0000000000000000 RCX: ffff8880a9ffa580
RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea0002597b80
RBP: ffffc90000dd7a18 R08: dffffc0000000000 R09: fffffbfff120248a
R10: fffffbfff120248a R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880a87834e8
 free_thread_stack+0x168/0x590 kernel/fork.c:280
 release_task_stack kernel/fork.c:440 [inline]
 put_task_stack+0xa3/0x130 kernel/fork.c:451
 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256
 context_switch kernel/sched/core.c:3388 [inline]
 __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081
 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338
 retint_kernel+0x1b/0x2b
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:618 [inline]
RIP: 0010:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline]
RIP: 0010:batadv_nc_worker+0x11e/0x600 net/batman-adv/network-coding.c:718
Code: 6c 01 01 75 17 e8 f2 a7 a2 f9 eb 50 e8 eb a7 a2 f9 eb 49 66 0f 1f 84 00 00 00 00 00 e8 2b be 8f f9 84 c0 74 07 e8 d2 a7 a2 f9 <eb> 30 e8 cb a7 a2 f9 c6 05 d0 17 6c 01 01 48 c7 c7 ab ae bb 88 be
RSP: 0018:ffffc90000dd7c78 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffffffff87d3f1ae RBX: 0000000000000001 RCX: ffff8880a9ffa580
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880aed37e20
RBP: ffffc90000dd7cd8 R08: dffffc0000000000 R09: ffffed1015da6fc5
R10: ffffed1015da6fc5 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888095a70000 R14: ffff88809ece8b80 R15: 0000000000000323
 process_one_work+0x7ef/0x10d0 kernel/workqueue.c:2264
 worker_thread+0xc01/0x1630 kernel/workqueue.c:2410
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352