rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10499 ticks this GP) idle=1e6/1/0x4000000000000002 softirq=262888/262888 fqs=5211 
rcu: 	 (t=10500 jiffies g=395777 q=692)
NMI backtrace for cpu 0
CPU: 0 PID: 13255 Comm: syz-executor3 Not tainted 4.19.0-rc8+ #64
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:162 [inline]
 rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1340
 print_cpu_stall.cold.78+0x2d3/0x524 kernel/rcu/tree.c:1478
 check_cpu_stall kernel/rcu/tree.c:1550 [inline]
 __rcu_pending kernel/rcu/tree.c:3276 [inline]
 rcu_pending kernel/rcu/tree.c:3319 [inline]
 rcu_check_callbacks+0xfd9/0x1990 kernel/rcu/tree.c:2665
 update_process_times+0x2d/0x70 kernel/time/timer.c:1636
 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1029 [inline]
 smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1054
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864
 </IRQ>
RIP: 0010:__pvclock_read_cycles arch/x86/include/asm/pvclock.h:85 [inline]
RIP: 0010:pvclock_clocksource_read+0x1dc/0x6a0 arch/x86/kernel/pvclock.c:87
Code: ff 4c 89 c6 48 c1 ea 03 83 e6 07 44 0f be 5b 1c 42 0f b6 14 22 48 89 f9 48 c1 e9 03 40 38 f2 42 0f b6 0c 21 40 0f 9e c6 84 d2 <0f> 95 c2 40 84 d6 0f 85 cb 02 00 00 83 e7 07 40 38 f9 40 0f 9e c6
RSP: 0018:ffff88017f216538 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 00000567483b195b RBX: ffffffff8a2fd000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8a2fd01b
RBP: ffff88017f216628 R08: ffffffff8a2fd018 R09: 0000000000000016
R10: fffffbfff145fa01 R11: 00000000ffffffff R12: dffffc0000000000
R13: ffffffff8a2fd003 R14: ffffffff8a2fd01d R15: ffffffff8a2fd010
 kvm_clock_read+0x18/0x30 arch/x86/kernel/kvmclock.c:103
 kvm_sched_clock_read+0x9/0x20 arch/x86/kernel/kvmclock.c:115
 paravirt_sched_clock arch/x86/include/asm/paravirt.h:175 [inline]
 sched_clock+0x31/0x40 arch/x86/kernel/tsc.c:245
 sched_clock_cpu+0x1b/0x1b0 kernel/sched/clock.c:370
 local_clock include/linux/sched/clock.h:84 [inline]
 cpu_clock_event_update+0x1b/0x50 kernel/events/core.c:9203
 cpu_clock_event_read+0x15/0x20 kernel/events/core.c:9236
 perf_output_read_group kernel/events/core.c:6108 [inline]
 perf_output_read+0x13a5/0x1920 kernel/events/core.c:6147
 perf_output_sample+0xd88/0x1df0 kernel/events/core.c:6189
 __perf_event_output kernel/events/core.c:6511 [inline]
 perf_event_output_forward+0x185/0x2d0 kernel/events/core.c:6524
 __perf_event_overflow+0x239/0x4c0 kernel/events/core.c:7768
 perf_swevent_overflow+0xad/0x150 kernel/events/core.c:7844
 perf_swevent_event+0x1f0/0x2e0 kernel/events/core.c:7877
 do_perf_sw_event kernel/events/core.c:7985 [inline]
 ___perf_sw_event+0x4a9/0x7c0 kernel/events/core.c:8016
 __perf_sw_event+0x4f/0x90 kernel/events/core.c:8028
 perf_sw_event include/linux/perf_event.h:1054 [inline]
 __do_page_fault+0x7ec/0xed0 arch/x86/mm/fault.c:1436
 do_page_fault+0xf2/0x7e0 arch/x86/mm/fault.c:1470
 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1161
RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20 arch/x86/lib/copy_user_64.S:180
Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 1f 00 c3 0f 1f 80 00 00 00 00 0f 1f 00 83 fa 40 0f 82 70 ff ff ff 89 d1 <f3> a4 31 c0 0f 1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 83
RSP: 0018:ffff88017f2176b8 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000008000 RCX: 0000000000003440
RDX: 0000000000008000 RSI: 0000000020f75000 RDI: ffff88019db64bc0
RBP: ffff88017f2176f0 R08: 0000000000000000 R09: 0000000000000200
R10: ffffed0033b6cfff R11: ffff88019db67fff R12: 0000000020f78440
R13: 0000000020f70440 R14: ffff88019db60000 R15: 00007ffffffff000
 _copy_from_iter_full+0x25e/0xd20 lib/iov_iter.c:724
 copy_from_iter_full include/linux/uio.h:124 [inline]
 skb_do_copy_data_nocache include/net/sock.h:1949 [inline]
 skb_copy_to_page_nocache include/net/sock.h:1975 [inline]
 kcm_sendmsg+0x179c/0x24b0 net/kcm/kcmsock.c:990
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:631
 sock_write_iter+0x35e/0x5c0 net/socket.c:900
 call_write_iter include/linux/fs.h:1808 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x6b8/0x9f0 fs/read_write.c:487
 vfs_write+0x1fc/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7819781c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 00000000fffffd70 RSI: 0000000020000440 RDI: 0000000000000005
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f78197826d4
R13: 00000000004c553a R14: 00000000004d8e68 R15: 00000000ffffffff
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-... } 10619 jiffies s: 15205 root: 0x1/.
rcu: blocking rcu_node structures:
Task dump for CPU 0:
syz-executor3   R  running task    20896 13255   5592 0x8000000c
Call Trace: