rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5673/1:b..l P8261/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=61537, q=204 ncpus=2)
task:syz-executor    state:R  running task     stack:23808 pid:8261  tgid:8261  ppid:8246   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 copy_pte_range mm/memory.c:1191 [inline]
 copy_pmd_range mm/memory.c:1252 [inline]
 copy_pud_range mm/memory.c:1289 [inline]
 copy_p4d_range mm/memory.c:1313 [inline]
 copy_page_range+0x1c95/0x57d0 mm/memory.c:1411
 dup_mmap kernel/fork.c:749 [inline]
 dup_mm kernel/fork.c:1672 [inline]
 copy_mm kernel/fork.c:1721 [inline]
 copy_process+0x7c57/0x8e90 kernel/fork.c:2387
 kernel_clone+0xfd/0x960 kernel/fork.c:2800
 __do_sys_clone+0xba/0x100 kernel/fork.c:2943
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9034d706d3
RSP: 002b:00007fff69626f28 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9034d706d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 00005555712067d0 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000007c326 R14: 000000000007b9ef R15: 00007fff696270b0
 </TASK>
task:kworker/u8:10   state:R  running task     stack:23968 pid:5673  tgid:5673  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:rcu_is_watching+0x80/0xc0 kernel/rcu/tree.c:727
Code: 89 da 48 c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02 83 e0 01 65 ff 0d 98 01 93 7e <74> 07 5b 5d c3 cc cc cc cc e8 c2 c7 8f ff 5b 5d c3 cc cc cc cc 48
RSP: 0018:ffffc90003407a88 EFLAGS: 00000286
RAX: 0000000000000001 RBX: ffff8880b9237ec8 RCX: ffffffff81687a4b
RDX: 0000000000000000 RSI: ffffffff8bb09800 RDI: ffffffff8d7b6b40
RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff2025e93
R10: ffffffff9012f49f R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8ddb5ba0 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x47b/0x560 kernel/locking/lockdep.c:5730
 rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0x16a/0x1060 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>
rcu: rcu_preempt kthread starved for 10484 jiffies! g61537 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:27680 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 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:106 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111