rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P2777/1:b..l P5093/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=120473, q=172 ncpus=2)
task:syz-executor.3  state:R  running task     stack:23296 pid:5093  tgid:5093  ppid:5077   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5376 [inline]
 __schedule+0xee2/0x59a0 kernel/sched/core.c:6688
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6865
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 copy_pte_range mm/memory.c:1106 [inline]
 copy_pmd_range mm/memory.c:1167 [inline]
 copy_pud_range mm/memory.c:1204 [inline]
 copy_p4d_range mm/memory.c:1228 [inline]
 copy_page_range+0x12af/0x3d50 mm/memory.c:1326
 dup_mmap+0x13f3/0x1d80 kernel/fork.c:758
 dup_mm kernel/fork.c:1684 [inline]
 copy_mm kernel/fork.c:1733 [inline]
 copy_process+0x6bff/0x73f0 kernel/fork.c:2499
 kernel_clone+0xfd/0x920 kernel/fork.c:2907
 __do_sys_clone+0xba/0x100 kernel/fork.c:3050
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f0e4a879b13
RSP: 002b:00007ffe7281f318 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0e4a879b13
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000555556883750 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
task:kworker/u4:9    state:R  running task     stack:23552 pid:2777  tgid:2777  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5376 [inline]
 __schedule+0xee2/0x59a0 kernel/sched/core.c:6688
 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:7008
 irqentry_exit+0x35/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5721
Code: c1 05 6d 8c 99 7e 83 f8 01 0f 85 b0 02 00 00 9c 58 f6 c4 02 0f 85 9b 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:ffffc9000a487ac8 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff92001490f5b RCX: 0000000000000001
RDX: 1ffff11004cbe8c9 RSI: ffffffff8aacbfe0 RDI: ffffffff8b0e5d40
RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff239b5d8
R10: ffffffff91cdaec7 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8cdad2a0 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:301 [inline]
 rcu_read_lock include/linux/rcupdate.h:747 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0x16e/0x10e0 net/batman-adv/network-coding.c:719
 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>
rcu: rcu_preempt kthread starved for 10153 jiffies! g120473 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27872 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5376 [inline]
 __schedule+0xee2/0x59a0 kernel/sched/core.c:6688
 __schedule_loop kernel/sched/core.c:6763 [inline]
 schedule+0xe7/0x270 kernel/sched/core.c:6778
 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1626
 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1825
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x1b/0x20 drivers/acpi/processor_idle.c:112