INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=9886, c=9885, q=671) All QSes seen, last rcu_preempt kthread activity 9456 (4294976685-4294967229), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.4 R running task 29208 21213 7982 0x00000000 Call Trace: sched_show_task.cold+0x333/0x39a kernel/sched/core.c:5165 print_other_cpu_stall kernel/rcu/tree.c:1501 [inline] check_cpu_stall kernel/rcu/tree.c:1616 [inline] __rcu_pending kernel/rcu/tree.c:3390 [inline] rcu_pending kernel/rcu/tree.c:3452 [inline] rcu_check_callbacks.cold+0xd29/0xd8d kernel/rcu/tree.c:2792 update_process_times+0x29/0x60 kernel/time/timer.c:1591 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165 tick_sched_timer+0x92/0x200 kernel/time/tick-sched.c:1223 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x30b/0xc80 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1079 [inline] smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1104 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x50/0x80 kernel/locking/spinlock.c:200 RSP: 0000:ffff8880a2507c68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff11e1253 RBX: 00000000004040a0 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff88809ca4cb84 RBP: ffff8880a92b08c8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8880a92b0208 R14: ffff8880a92b0200 R15: 000000000000000b spin_unlock_irq include/linux/spinlock.h:367 [inline] get_signal+0x16ce/0x1ca0 kernel/signal.c:2426 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode+0x1af/0x210 arch/x86/entry/common.c:199 retint_user+0x8/0x18 RIP: 0033:0x7ffd8e16eb4f RSP: 002b:00007fab79dcb220 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 00007ffd8e16eb4f RCX: 00000000004c086d RDX: 0000000000057ebf RSI: 0000000000012f6c RDI: 00000000004d056a RBP: 0000000000403bad R08: 0000000000000000 R09: 000000000000000e R10: 001a85ffceb48cf2 R11: 0000000000000001 R12: 000000000056bf6c R13: 00007ffd8e16eb4f R14: 00007fab79dcb300 R15: 0000000000022000 rcu_preempt kthread starved for 9456 jiffies! g9886 c9885 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1 rcu_preempt R running task 30008 8 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x4af/0xe90 kernel/time/timer.c:1747 rcu_gp_kthread+0xc0a/0x1e60 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404