INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=31218, c=31217, q=254) All QSes seen, last rcu_preempt kthread activity 10504 (4295052025-4295041521), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.4 R running task 28800 8520 6355 0x0000000c Call Trace: sched_show_task kernel/sched/core.c:5168 [inline] sched_show_task.cold+0x2e3/0x347 kernel/sched/core.c:5143 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+0xd3f/0xdaa kernel/rcu/tree.c:2792 update_process_times+0x29/0x60 kernel/time/timer.c:1590 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:unwind_next_frame+0x2df/0x17a0 arch/x86/kernel/unwind_orc.c:349 RSP: 0018:ffff8880aea077e0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000015 RBX: ffff8880aea07890 RCX: ffffffff8640b569 RDX: 0000000000000002 RSI: ffffffff8950bf6e RDI: ffffffff88e1f3b4 RBP: 1ffff11015d40f03 R08: ffffffff8950bf8a R09: ffff888065717b08 R10: ffff8880aea078c5 R11: 0000000000058071 R12: ffffffff8950bf86 R13: ffff8880aea078c8 R14: ffff8880aea078d8 R15: 0000000000000001 __save_stack_trace+0x6b/0xd0 arch/x86/kernel/stacktrace.c:44 save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529 slab_post_alloc_hook mm/slab.h:442 [inline] slab_alloc_node mm/slab.c:3333 [inline] kmem_cache_alloc_node+0x135/0x7a0 mm/slab.c:3640 __alloc_skb+0x9a/0x4c0 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:980 [inline] mrp_pdu_init net/802/mrp.c:303 [inline] mrp_pdu_append_vecattr_event+0x6f1/0xfa0 net/802/mrp.c:402 mrp_attr_event+0x151/0x1e0 net/802/mrp.c:497 mrp_mad_event+0x47/0x60 net/802/mrp.c:577 mrp_join_timer+0x2f/0x80 net/802/mrp.c:594 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279 expire_timers kernel/time/timer.c:1318 [inline] __run_timers kernel/time/timer.c:1636 [inline] __run_timers kernel/time/timer.c:1604 [inline] run_timer_softirq+0x52a/0x1390 kernel/time/timer.c:1649 __do_softirq+0x254/0x9bf kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15b/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:lock_acquire+0x1ec/0x3f0 kernel/locking/lockdep.c:3997 RSP: 0018:ffff888065717b08 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff0fa2cd1 RBX: ffff8880985a4040 RCX: 0000000095801e8e RDX: dffffc0000000000 RSI: ffff8880985a48c0 RDI: 0000000000000282 RBP: ffffc90000c70c20 R08: 000000000000292b R09: ffffffff8a0711d8 R10: ffff8880985a48c0 R11: ffff8880985a4040 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] futex_wake+0x167/0x3d0 kernel/futex.c:1694 do_futex+0x264/0x1850 kernel/futex.c:3924 SYSC_futex kernel/futex.c:3980 [inline] SyS_futex+0x1e8/0x2c0 kernel/futex.c:3948 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c829 RSP: 002b:00007ff51e839cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000078bf08 RCX: 000000000045c829 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000078bf0c RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffda667313f R14: 00007ff51e83a9c0 R15: 000000000078bf0c rcu_preempt kthread starved for 10558 jiffies! g31218 c31217 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 rcu_preempt R running task 29920 8 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404