rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=214801, q=305) rcu: All QSes seen, last rcu_preempt kthread activity 10497 (4295085010-4295074513), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.2 R running task 26912 28153 27765 0x0000000a Call Trace: sched_show_task.cold+0x332/0x396 syzkaller/managers/linux-4-19/kernel/kernel/sched/core.c:5337 print_other_cpu_stall syzkaller/managers/linux-4-19/kernel/kernel/rcu/tree.c:1430 [inline] check_cpu_stall syzkaller/managers/linux-4-19/kernel/kernel/rcu/tree.c:1557 [inline] __rcu_pending syzkaller/managers/linux-4-19/kernel/kernel/rcu/tree.c:3293 [inline] rcu_pending syzkaller/managers/linux-4-19/kernel/kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0xb37/0xe19 syzkaller/managers/linux-4-19/kernel/kernel/rcu/tree.c:2682 update_process_times+0x2a/0x70 syzkaller/managers/linux-4-19/kernel/kernel/time/timer.c:1650 tick_sched_handle+0x9b/0x180 syzkaller/managers/linux-4-19/kernel/kernel/time/tick-sched.c:168 tick_sched_timer+0xfc/0x290 syzkaller/managers/linux-4-19/kernel/kernel/time/tick-sched.c:1278 __run_hrtimer syzkaller/managers/linux-4-19/kernel/kernel/time/hrtimer.c:1401 [inline] __hrtimer_run_queues+0x3f6/0xe60 syzkaller/managers/linux-4-19/kernel/kernel/time/hrtimer.c:1463 hrtimer_interrupt+0x32a/0x930 syzkaller/managers/linux-4-19/kernel/kernel/time/hrtimer.c:1521 local_apic_timer_interrupt syzkaller/managers/linux-4-19/kernel/arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x10c/0x550 syzkaller/managers/linux-4-19/kernel/arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 syzkaller/managers/linux-4-19/kernel/arch/x86/entry/entry_64.S:894 RIP: 0010:pv_wait_head_or_lock syzkaller/managers/linux-4-19/kernel/kernel/locking/qspinlock_paravirt.h:435 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x3a6/0xae0 syzkaller/managers/linux-4-19/kernel/kernel/locking/qspinlock.c:474 Code: eb c6 45 01 01 41 bc 00 80 00 00 48 c1 e9 03 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c f3 90 <41> 83 ec 01 0f 84 38 04 00 00 41 0f b6 45 00 38 d8 7f 08 84 c0 0f RSP: 0018:ffff888052e9f628 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffffffff1404154 RDX: 0000000000000001 RSI: ffffffff81677d85 RDI: 0000000000000286 RBP: ffffffff8a020aa0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000003be2 R13: fffffbfff1404154 R14: 0000000000000001 R15: ffff8880ba12bd80 pv_queued_spin_lock_slowpath syzkaller/managers/linux-4-19/kernel/./arch/x86/include/asm/paravirt.h:679 [inline] queued_spin_lock_slowpath syzkaller/managers/linux-4-19/kernel/./arch/x86/include/asm/qspinlock.h:53 [inline] queued_spin_lock syzkaller/managers/linux-4-19/kernel/./include/asm-generic/qspinlock.h:88 [inline] do_raw_spin_lock+0x189/0x220 syzkaller/managers/linux-4-19/kernel/kernel/locking/spinlock_debug.c:113 spin_lock syzkaller/managers/linux-4-19/kernel/./include/linux/spinlock.h:329 [inline] alloc_huge_page+0x3a6/0xea0 syzkaller/managers/linux-4-19/kernel/mm/hugetlb.c:2063 hugetlb_no_page+0x2b0/0x1090 syzkaller/managers/linux-4-19/kernel/mm/hugetlb.c:3823 hugetlb_fault+0xc68/0x1200 syzkaller/managers/linux-4-19/kernel/mm/hugetlb.c:3992 follow_hugetlb_page+0x5da/0x11d0 syzkaller/managers/linux-4-19/kernel/mm/hugetlb.c:4301 __get_user_pages+0x37e/0x1640 syzkaller/managers/linux-4-19/kernel/mm/gup.c:713 populate_vma_page_range+0x200/0x290 syzkaller/managers/linux-4-19/kernel/mm/gup.c:1234 __mm_populate+0x1ea/0x350 syzkaller/managers/linux-4-19/kernel/mm/gup.c:1282 mm_populate syzkaller/managers/linux-4-19/kernel/./include/linux/mm.h:2335 [inline] vm_mmap_pgoff+0x1e2/0x200 syzkaller/managers/linux-4-19/kernel/mm/util.c:362 ksys_mmap_pgoff+0x298/0x5a0 syzkaller/managers/linux-4-19/kernel/mm/mmap.c:1580 do_syscall_64+0xf9/0x620 syzkaller/managers/linux-4-19/kernel/arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f512a82d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000002000006 RSI: 0000000000400017 RDI: 0000000020200000 RBP: 00000000004b069f R08: 0000000000000004 R09: 0000000000000000 R10: 0000000000002012 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fffb0902ecf R14: 00007f512a82d300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10538 jiffies! g214801 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29208 10 2 0x80000000 Call Trace: context_switch syzkaller/managers/linux-4-19/kernel/kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 syzkaller/managers/linux-4-19/kernel/kernel/sched/core.c:3517 schedule+0x8d/0x1b0 syzkaller/managers/linux-4-19/kernel/kernel/sched/core.c:3561 schedule_timeout+0x4cf/0xfe0 syzkaller/managers/linux-4-19/kernel/kernel/time/timer.c:1818 rcu_gp_kthread+0xdad/0x21c0 syzkaller/managers/linux-4-19/kernel/kernel/rcu/tree.c:2202 kthread+0x33f/0x460 syzkaller/managers/linux-4-19/kernel/kernel/kthread.c:259 ret_from_fork+0x24/0x30 syzkaller/managers/linux-4-19/kernel/arch/x86/entry/entry_64.S:415