kvm: KVM_SET_TSS_ADDR need to be called before entering vcpu
BUG: unable to handle kernel paging request at fffffffffffffff8
IP: copy_user_handle_tail+0x31/0x80 arch/x86/lib/usercopy_64.c:69
PGD 5e28067 P4D 5e28067 PUD 5e2a067 PMD 0 
Oops: 0002 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 3318 Comm: syz-executor7 Not tainted 4.15.0-rc1-mm1+ #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801c49b00c0 task.stack: ffff8801c4a98000
RIP: 0010:copy_user_handle_tail+0x31/0x80 arch/x86/lib/usercopy_64.c:69
RSP: 0018:ffff8801c4a9fac0 EFLAGS: 00010246
RAX: 0000000000010000 RBX: 0000000000000000 RCX: ffffffff851520f5
RDX: 0000000000000087 RSI: ffffc900017c6000 RDI: ffff8801c4a9fd80
RBP: ffff8801c4a9fae8 R08: 00000000201c9000 R09: ffffed0038953fb2
R10: 0000000000000002 R11: ffffed0038953fb1 R12: 0000000000000010
R13: ffff8801c4a9fd80 R14: 0000000020000001 R15: 0000000020000000
FS:  00007f3d77154700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffff8 CR3: 00000001c4f34000 CR4: 00000000001426e0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 00000000000b0602
Call Trace:
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:55 [inline]
 _copy_from_user+0xc5/0x110 lib/usercopy.c:13
 copy_from_user include/linux/uaccess.h:147 [inline]
 rw_copy_check_uvector+0x81/0x280 fs/read_write.c:760
 import_iovec+0xc8/0x430 lib/iov_iter.c:1398
 process_vm_rw+0x166/0x330 mm/process_vm_access.c:275
 SYSC_process_vm_writev mm/process_vm_access.c:308 [inline]
 SyS_process_vm_writev+0x42/0x50 mm/process_vm_access.c:303
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x4529d9
RSP: 002b:00007f3d77153c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000137
RAX: ffffffffffffffda RBX: cccccccccccccccd RCX: 00000000004529d9
RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 00000000000005a2 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000fd0 R11: 0000000000000212 R12: 00000000006f57d0
R13: 00000000ffffffff R14: 00007f3d771546d4 R15: 0000000000000000
Code: 41 56 41 55 41 54 41 89 d4 53 49 89 fd 49 89 f7 e8 c5 0a 5b fc 45 85 e4 74 3d e8 bb 0a 5b fc 0f 1f 00 31 db 4d 8d 77 01 45 8a 3f <0f> 1f 00 85 db 75 2a e8 a3 0a 5b fc 0f 1f 00 45 88 7d 00 0f 1f 
RIP: copy_user_handle_tail+0x31/0x80 arch/x86/lib/usercopy_64.c:69 RSP: ffff8801c4a9fac0
CR2: fffffffffffffff8
---[ end trace cffb8d61472b5174 ]---