rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3588/1:b..l (detected by 0, t=10502 jiffies, g=11189, q=106) task:udevd state:R running task stack: 0 pid: 3588 ppid: 1 flags:0x00000004 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 preempt_schedule_common+0x140/0x260 kernel/sched/core.c:6552 preempt_schedule+0x64/0x84 kernel/sched/core.c:6577 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x114/0x158 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline] __wake_up_common_lock kernel/sched/wait.c:140 [inline] __wake_up_sync_key+0x124/0x1ac kernel/sched/wait.c:205 sock_def_readable+0x150/0x278 net/core/sock.c:3092 __netlink_sendskb net/netlink/af_netlink.c:1277 [inline] netlink_sendskb+0x98/0x168 net/netlink/af_netlink.c:1283 netlink_unicast+0x328/0x938 net/netlink/af_netlink.c:1371 netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x584/0x870 net/socket.c:2431 ___sys_sendmsg+0x214/0x294 net/socket.c:2485 __sys_sendmsg net/socket.c:2514 [inline] __do_sys_sendmsg net/socket.c:2523 [inline] __se_sys_sendmsg net/socket.c:2521 [inline] __arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2521 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 rcu: rcu_preempt kthread timer wakeup didn't happen for 7759 jiffies! g11189 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=5056 rcu: rcu_preempt kthread starved for 7760 jiffies! g11189 f0x2 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: 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:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 schedule+0x11c/0x1c8 kernel/sched/core.c:6459 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-executor.0 state:R running task stack: 0 pid: 5191 ppid: 3990 flags:0x00000001 Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 sched_show_task+0x43c/0x574 kernel/sched/core.c:8640 dump_cpu_task+0x84/0xa8 kernel/sched/core.c:10914 rcu_check_gp_kthread_starvation+0x1f0/0x254 kernel/rcu/tree_stall.h:488 print_other_cpu_stall+0x202c/0x2290 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+0x1894/0x1b8c kernel/rcu/tree.c:2619 update_process_times+0x1d4/0x270 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x340/0x4f8 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x458/0xca4 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x2c0/0xb64 kernel/time/hrtimer.c:1812 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/0x7fc kernel/irq/chip.c:933 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq_desc kernel/irq/irqdesc.c:651 [inline] handle_domain_irq+0xec/0x178 kernel/irq/irqdesc.c:706 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:758 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899 do_interrupt_handler+0x74/0x94 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_restore arch/arm64/include/asm/irqflags.h:122 [inline] lock_acquire+0x280/0x77c kernel/locking/lockdep.c:5626 __might_fault+0xc8/0x128 mm/memory.c:5328 restore_sigframe arch/arm64/kernel/signal.c:503 [inline] __arm64_sys_rt_sigreturn+0x3e8/0x22ec arch/arm64/kernel/signal.c:555 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584