rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P1674/1:b..l P4534/1:b..l
	(detected by 1, t=10502 jiffies, g=11249, q=176)
task:kworker/1:6     state:R  running task     stack:    0 pid: 4534 ppid:     2 flags:0x00000008
Workqueue: events nsim_fib_event_work
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6373
 preempt_schedule_irq+0x90/0x274 kernel/sched/core.c:6777
 arm64_preempt_schedule_irq+0x174/0x2c4 arch/arm64/kernel/entry-common.c:260
 el1_interrupt+0x40/0x58 arch/arm64/kernel/entry-common.c:463
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470
 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522
 arch_local_irq_enable arch/arm64/include/asm/irqflags.h:35 [inline]
 __local_bh_enable_ip+0x238/0x470 kernel/softirq.c:388
 local_bh_enable+0x28/0x34 include/linux/bottom_half.h:32
 rht_assign_unlock+0xa0/0xc0 include/linux/rhashtable.h:404
 __rhashtable_insert_fast include/linux/rhashtable.h:788 [inline]
 rhashtable_insert_fast+0x57c/0xb94 include/linux/rhashtable.h:825
 nsim_fib4_rt_add drivers/net/netdevsim/fib.c:360 [inline]
 nsim_fib4_rt_insert drivers/net/netdevsim/fib.c:430 [inline]
 nsim_fib4_event drivers/net/netdevsim/fib.c:462 [inline]
 nsim_fib_event drivers/net/netdevsim/fib.c:882 [inline]
 nsim_fib_event_work+0x1464/0x33c4 drivers/net/netdevsim/fib.c:1481
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 process_scheduled_works kernel/workqueue.c:2373 [inline]
 worker_thread+0xb88/0x1034 kernel/workqueue.c:2459
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
task:kworker/u4:5    state:R  running task     stack:    0 pid: 1674 ppid:     2 flags:0x00000008
Workqueue: writeback wb_workfn (flush-259:0)
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6373
 preempt_schedule_notrace+0xc4/0x1a8 kernel/sched/core.c:6628
 rcu_is_watching+0x10c/0x18c kernel/rcu/tree.c:1124
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x100/0x77c kernel/locking/lockdep.c:5594
 rcu_lock_acquire+0x40/0x4c include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 blk_try_enter_queue+0x30/0x630 block/blk-core.c:415
 bio_queue_enter block/blk-core.c:474 [inline]
 __submit_bio+0x168/0x664 block/blk-core.c:908
 __submit_bio_noacct_mq block/blk-core.c:997 [inline]
 submit_bio_noacct+0x680/0x7dc block/blk-core.c:1027
 submit_bio+0x394/0x68c block/blk-core.c:1089
 ext4_io_submit+0x130/0x1e0 fs/ext4/page-io.c:381
 ext4_writepages+0xa38/0x36fc fs/ext4/inode.c:2786
 do_writepages+0x39c/0x5ec mm/page-writeback.c:2386
 __writeback_single_inode+0x148/0x13a4 fs/fs-writeback.c:1647
 writeback_sb_inodes+0x94c/0x1654 fs/fs-writeback.c:1930
 __writeback_inodes_wb+0x110/0x39c fs/fs-writeback.c:2001
 wb_writeback+0x410/0xfc8 fs/fs-writeback.c:2106
 wb_check_old_data_flush fs/fs-writeback.c:2206 [inline]
 wb_do_writeback fs/fs-writeback.c:2259 [inline]
 wb_workfn+0xbb4/0x1070 fs/fs-writeback.c:2288
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 worker_thread+0x910/0x1034 kernel/workqueue.c:2457
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g11249 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=4049
rcu: rcu_preempt kthread starved for 10502 jiffies! g11249 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:    0 pid:   15 ppid:     2 flags:0x00000008
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6373
 schedule+0x11c/0x1c8 kernel/sched/core.c:6456
 schedule_timeout+0x1d8/0x344 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x26c/0x13d4 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xc4/0x2c4 kernel/rcu/tree.c:2145
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
rcu: Stack dump where RCU GP kthread last ran:
Task dump for CPU 0:
task:syz.3.18        state:R  running task     stack:    0 pid: 4856 ppid:  4526 flags:0x00000000
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 0xffff0000d9a984c8