rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5370/1:b..l P12/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=11617, q=859 ncpus=2)
task:kworker/u8:1    state:R  running task     stack:24592 pid:12    tgid:12    ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:debug_lockdep_rcu_enabled+0x26/0x40 kernel/rcu/update.c:320
Code: 90 90 90 90 f3 0f 1e fa 8b 05 4a d5 00 05 85 c0 74 20 8b 05 44 05 01 05 85 c0 74 16 65 48 8b 05 40 d1 f1 74 8b 80 dc 0a 00 00 <85> c0 0f 94 c0 0f b6 c0 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00
RSP: 0018:ffffc90000117b88 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff88802d3513f0 RCX: ffffffff8ad68db9
RDX: ffff888017a85a00 RSI: ffffffff8ad689db RDI: 0000000000000001
RBP: 000000000000027e R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88807e4d9ec0
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000001
 rcu_read_unlock include/linux/rcupdate.h:867 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0x8c0/0x10f0 net/batman-adv/network-coding.c:719
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
task:syz.3.17        state:R  running task     stack:25216 pid:5370  tgid:5369  ppid:5220   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x1f2/0x560 kernel/locking/lockdep.c:5727
Code: c1 05 4a 11 9a 7e 83 f8 01 0f 85 ea 02 00 00 9c 58 f6 c4 02 0f 85 d5 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc9000348f048 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff92000691e0b RCX: 0000000000000001
RDX: 0000000000000001 RSI: ffffffff8b4cc800 RDI: ffffffff8bb08ec0
RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff28c5ad8
R10: ffffffff9462d6c7 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8ddb5ce0 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 mt_find+0x16a/0xa20 lib/maple_tree.c:6930
 find_vma+0xc0/0x140 mm/mmap.c:2019
 gup_vma_lookup+0x24/0x220 mm/gup.c:1343
 __get_user_pages+0x261/0x15c0 mm/gup.c:1461
 __get_user_pages_locked mm/gup.c:1760 [inline]
 get_dump_page+0xfb/0x220 mm/gup.c:2278
 dump_user_range+0x135/0x8a0 fs/coredump.c:952
 elf_core_dump+0x27c1/0x39a0 fs/binfmt_elf.c:2116
 do_coredump+0x29c5/0x3de0 fs/coredump.c:767
 get_signal+0x23d4/0x2770 kernel/signal.c:2902
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f02d8d799f9
RSP: 002b:00007f02d87ff038 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007f02d8f15f80 RCX: 00007f02d8d799f9
RDX: 000000000000000d RSI: 0000000000000084 RDI: 0000000000000009
RBP: 00007f02d8de78ee R08: 0000000020000200 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f02d8f15f80 R15: 00007ffcc3b60b38
 </TASK>
rcu: rcu_preempt kthread starved for 10562 jiffies! g11617 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:26144 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6621
 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </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:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111