rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=cfa/1/0x4000000000000000 softirq=55487/55488 fqs=38 
	(detected by 1, t=10502 jiffies, g=93529, q=172)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6956 Comm: syz-executor.5 Not tainted 5.9.0-rc4-next-20200910-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_acquire+0x39e/0x55d0 kernel/locking/lockdep.c:4744
Code: 41 09 c1 48 b8 00 00 00 00 00 fc ff df 44 89 4d 20 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 0d 11 00 00 <8b> 84 24 38 01 00 00 89 45 24 4c 8b 6c 24 10 be 08 00 00 00 41 81
RSP: 0018:ffffc90000007b58 EFLAGS: 00000046
RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880640acbbc
RBP: ffff8880640acb98 R08: 0000000000000001 R09: 00000000000a402c
R10: 00000000000000c8 R11: 0000000000000000 R12: ffff8880640ac1c0
R13: 0000000000000000 R14: ffffffff89e70ac0 R15: 0000000000024000
FS:  0000000001d36940(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000016a3b73 CR3: 0000000064082000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5398
 rcu_lock_acquire include/linux/rcupdate.h:248 [inline]
 rcu_read_lock include/linux/rcupdate.h:641 [inline]
 advance_sched+0x4d9/0x990 net/sched/sch_taprio.c:752
 __run_hrtimer kernel/time/hrtimer.c:1524 [inline]
 __hrtimer_run_queues+0x693/0xea0 kernel/time/hrtimer.c:1588
 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0x13e/0x520 arch/x86/kernel/apic/apic.c:1097
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x10/0x60 kernel/kcov.c:197
Code: 36 cd 24 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 48 8b 14 25 c0 fe 01 00 65 8b 05 60 4c 8f 7e <a9> 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 35 8b 82 4c 14 00 00
RSP: 0018:ffffc900069b77d8 EFLAGS: 00000246
RAX: 0000000080000002 RBX: dffffc0000000000 RCX: ffffffff81a438b4
RDX: ffff8880640ac1c0 RSI: 00007ffb4aab3000 RDI: ffff88809609f840
RBP: 1ffff92000d36efc R08: 0000000000000000 R09: ffffea0001980f47
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809609f840
R13: 00007ffb4aab3000 R14: 0000000000000000 R15: 0000000000000018
 vm_normal_page+0x6b/0x380 mm/memory.c:598
 copy_one_pte mm/memory.c:803 [inline]
 copy_pte_range mm/memory.c:854 [inline]
 copy_pmd_range mm/memory.c:905 [inline]
 copy_pud_range mm/memory.c:939 [inline]
 copy_p4d_range mm/memory.c:961 [inline]
 copy_page_range+0xf1c/0x2820 mm/memory.c:1023
 dup_mmap kernel/fork.c:592 [inline]
 dup_mm+0x98f/0x1300 kernel/fork.c:1353
 copy_mm kernel/fork.c:1409 [inline]
 copy_process+0x2a85/0x6de0 kernel/fork.c:2087
 kernel_clone+0xe5/0xae0 kernel/fork.c:2448
 __do_sys_clone+0xc8/0x110 kernel/fork.c:2565
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45bb8a
Code: f7 d8 64 89 04 25 d4 02 00 00 64 4c 8b 0c 25 10 00 00 00 31 d2 4d 8d 91 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 f5 00 00 00 85 c0 41 89 c5 0f 85 fc 00 00
RSP: 002b:00007fff6f0162b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fff6f0162b0 RCX: 000000000045bb8a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007fff6f0162f0 R08: 0000000000000001 R09: 0000000001d36940
R10: 0000000001d36c10 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 00007fff6f016340
rcu: rcu_preempt kthread starved for 10425 jiffies! g93529 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:28856 pid:   10 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3777 [inline]
 __schedule+0xea5/0x21b0 kernel/sched/core.c:4526
 schedule+0xcf/0x270 kernel/sched/core.c:4604
 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879
 rcu_gp_fqs_loop kernel/rcu/tree.c:1931 [inline]
 rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2105
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294