syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3320/1:b..l
	(detected by 1, t=10502 jiffies, g=3833, q=267)
task:kworker/0:2     state:R  running task     stack:    0 pid: 3320 ppid:     2 flags:0x00000008
Workqueue: mld mld_ifc_work
Call trace:
 __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xe00/0x1c0c kernel/sched/core.c:6376
 preempt_schedule_irq+0x90/0x214 kernel/sched/core.c:6780
 arm64_preempt_schedule_irq+0x14c/0x21c 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
 xfrm_lookup_with_ifid+0x990/0x1e9c net/xfrm/xfrm_policy.c:3146
 xfrm_lookup+0x4c/0x64 net/xfrm/xfrm_policy.c:3220
 icmp6_dst_alloc+0x3b8/0x484 net/ipv6/route.c:3289
 mld_sendpack+0x6a8/0x1058 net/ipv6/mcast.c:1815
 mld_send_cr net/ipv6/mcast.c:2127 [inline]
 mld_ifc_work+0x784/0xad8 net/ipv6/mcast.c:2659
 process_one_work+0x79c/0x1140 kernel/workqueue.c:2310
 worker_thread+0x8f4/0x101c kernel/workqueue.c:2457
 kthread+0x374/0x454 kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
rcu: rcu_preempt kthread starved for 10498 jiffies! g3833 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:    0 pid:   15 ppid:     2 flags:0x00000008
Call trace:
 __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xe00/0x1c0c kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 schedule_timeout+0x180/0x2c8 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x25c/0x11f0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xc4/0x2a8 kernel/rcu/tree.c:2145
 kthread+0x374/0x454 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 1:
task:syz-executor828 state:R  running task     stack:    0 pid: 4054 ppid:  4030 flags:0x00000000
Call trace:
 dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 sched_show_task+0x3c8/0x4b4 kernel/sched/core.c:8640
 dump_cpu_task+0x84/0xa8 kernel/sched/core.c:10927
 rcu_check_gp_kthread_starvation+0x1e8/0x274 kernel/rcu/tree_stall.h:488
 print_other_cpu_stall+0x1a24/0x1c10 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0x1558/0x1810 kernel/rcu/tree.c:2619
 update_process_times+0x1c4/0x260 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x30c/0x4bc kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1690 [inline]
 __hrtimer_run_queues+0x3fc/0xb6c kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x2bc/0xb5c kernel/time/hrtimer.c:1816
 timer_handler drivers/clocksource/arm_arch_timer.c:659 [inline]
 arch_timer_handler_virt+0x74/0x88 drivers/clocksource/arm_arch_timer.c:670
 handle_percpu_devid_irq+0x29c/0x76c kernel/irq/chip.c:930
 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
 handle_irq_desc kernel/irq/irqdesc.c:652 [inline]
 handle_domain_irq+0x144/0x1fc kernel/irq/irqdesc.c:707
 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:765
 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899
 do_interrupt_handler+0x6c/0x88 arch/arm64/kernel/entry-common.c:267
 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454
 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]
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
 _raw_spin_unlock_irq+0xa0/0x128 kernel/locking/spinlock.c:202
 spin_unlock_irq include/linux/spinlock.h:413 [inline]
 get_signal+0xfac/0x1340 kernel/signal.c:2903
 do_signal arch/arm64/kernel/signal.c:890 [inline]
 do_notify_resume+0x29c/0x3128 arch/arm64/kernel/signal.c:943
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
 el0_svc+0xf0/0x1e0 arch/arm64/kernel/entry-common.c:609
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584