rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=6001, q=98) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294953542-4294943040), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.0 R running task 24392 8081 8080 0x0000400a Call Trace: sched_show_task+0x40f/0x560 kernel/sched/core.c:5954 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline] check_cpu_stall kernel/rcu/tree_stall.h:538 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0x1861/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:free_thread_stack+0x141/0x590 kernel/fork.c:280 Code: a2 60 00 e9 5d 04 00 00 e8 5c 2d 2e 00 48 89 df 31 f6 e8 42 af 6e 00 43 80 3c 2e 00 74 08 4c 89 e7 e8 43 a4 69 00 49 8b 1c 24 <48> 83 c3 08 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 RSP: 0018:ffffc90002167c60 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffff8880a7438b80 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0002625740 RBP: ffffc90002167c98 R08: dffffc0000000000 R09: fffffbfff12877ed R10: fffffbfff12877ed R11: 0000000000000000 R12: ffff8880a7438c20 R13: dffffc0000000000 R14: 1ffff11014e87184 R15: ffff88809854d468 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_common kernel/sched/core.c:4236 [inline] preempt_schedule+0xdb/0x120 kernel/sched/core.c:4261 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50 __raw_read_unlock include/linux/rwlock_api_smp.h:227 [inline] _raw_read_unlock+0x3a/0x40 kernel/locking/spinlock.c:255 kill_something_info kernel/signal.c:1586 [inline] __do_sys_kill kernel/signal.c:3640 [inline] __se_sys_kill+0x5e9/0x6c0 kernel/signal.c:3634 __x64_sys_kill+0x5b/0x70 kernel/signal.c:3634 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x422a17 Code: 44 00 00 48 c7 c2 d4 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 b8 3e 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 dd 32 ff ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffed0541e08 EFLAGS: 00000293 ORIG_RAX: 000000000000003e RAX: ffffffffffffffda RBX: 0000000000000064 RCX: 0000000000422a17 RDX: 0000000000000bb8 RSI: 0000000000000009 RDI: 00000000fffffffe RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000001675940 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005 R13: 00007ffed0541e40 R14: 000000000000e5db R15: 00007ffed0541e50 rcu: rcu_preempt kthread starved for 10502 jiffies! g6001 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29104 10 2 0x80004008 Call Trace: context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352