INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=63789, c=63788, q=43) All QSes seen, last rcu_preempt kthread activity 5516 (4295128300-4295122784), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.4 R running task 28400 12853 6359 0x8000000c 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+0x7c/0x17a0 arch/x86/kernel/unwind_orc.c:326 RSP: 0018:ffff8880aeb07800 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000001 RBX: ffff8880aeb078b0 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffff8880aeb077b8 RDI: 0000000000000001 RBP: 1ffff11015d60f07 R08: 0000000000000001 R09: ffff8881fce17c10 R10: ffff8880aeb078e5 R11: 0000000000058071 R12: ffff8881fce17c48 R13: ffff8881fce10000 R14: ffff8881fce17c48 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 __do_kmalloc_node mm/slab.c:3682 [inline] __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3696 __kmalloc_reserve.isra.0+0x35/0xd0 net/core/skbuff.c:137 __alloc_skb+0xca/0x4c0 net/core/skbuff.c:205 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:pud_trans_huge arch/x86/include/asm/pgtable.h:245 [inline] RIP: 0010:zap_pud_range mm/memory.c:1463 [inline] RIP: 0010:zap_p4d_range mm/memory.c:1494 [inline] RIP: 0010:unmap_page_range+0x246/0x1930 mm/memory.c:1515 RSP: 0018:ffff8881fce177d8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: ffff88808b8dfbd0 RBX: 000000008b8df007 RCX: 00007f5ea142b000 RDX: 1ffff1101171bf7a RSI: ffff88800e4e4630 RDI: 000000009b913067 RBP: 000000008b8df067 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8882189b6b28 R11: ffff8882189b6280 R12: 00007f7fffffffff R13: 00007f5ea122b000 R14: 00007f5ea122b000 R15: ffff88800e4e4680 unmap_single_vma+0x147/0x2b0 mm/memory.c:1560 unmap_vmas+0x9d/0x160 mm/memory.c:1590 exit_mmap+0x26d/0x4b0 mm/mmap.c:3056 __mmput kernel/fork.c:930 [inline] mmput+0x103/0x420 kernel/fork.c:951 exit_mm kernel/exit.c:545 [inline] do_exit+0x933/0x2b00 kernel/exit.c:845 do_group_exit+0x100/0x310 kernel/exit.c:955 get_signal+0x385/0x1ca0 kernel/signal.c:2423 do_signal+0x7c/0x1690 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x159/0x220 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c829 RSP: 002b:00007f5ea0429c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000048 RAX: 0000000000000000 RBX: 00000000004dbc80 RCX: 000000000045c829 RDX: 0000000000002000 RSI: 0000000000000004 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000000c7 R14: 00000000004c353a R15: 00007f5ea042a6d4 rcu_preempt kthread starved for 5516 jiffies! g63789 c63788 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1 rcu_preempt R running task 29392 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