syzbot

usercopy: kernel memory overwrite attempt detected to ffff8801d27b9bd4 (kvm_vcpu) (1320 bytes)
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kernel BUG at mm/usercopy.c:84!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 2990 Comm: syzkaller600051 Not tainted 4.14.0-rc5-mm1+ #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d1d60080 task.stack: ffff8801d1e68000
RIP: 0010:report_usercopy mm/usercopy.c:76 [inline]
RIP: 0010:__check_object_size+0x3a2/0x4f0 mm/usercopy.c:276
RSP: 0018:ffff8801d1e6f148 EFLAGS: 00010286
RAX: 000000000000005e RBX: ffffffff8511a100 RCX: 0000000000000000
RDX: 000000000000005e RSI: 1ffff1003a3cdde9 RDI: ffffed003a3cde1d
RBP: ffff8801d1e6f238 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8511a0c0
R13: ffff8801d27b9bd4 R14: 0000000000000528 R15: ffffea000749ee00
FS:  000000000105e880(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020237000 CR3: 00000001d3234000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 check_object_size include/linux/thread_info.h:111 [inline]
 check_copy_size include/linux/thread_info.h:142 [inline]
 copy_from_user include/linux/uaccess.h:145 [inline]
 kvm_vcpu_ioctl_set_cpuid2+0x75/0x1a0 arch/x86/kvm/cpuid.c:245
 kvm_arch_vcpu_ioctl+0x1718/0x4710 arch/x86/kvm/x86.c:3521
 kvm_vcpu_ioctl+0x240/0x1010 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2703
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x442f87
RSP: 002b:00007ffe1675e638 EFLAGS: 00000217 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffe1675ed10 RCX: 0000000000442f87
RDX: 00007ffe1675ed10 RSI: 000000004008ae90 RDI: 0000000000000005
RBP: 0000000000000082 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000217 R12: 00000000004040a0
R13: 0000000000404130 R14: 0000000000000000 R15: 0000000000000000
Code: 48 0f 44 da e8 e0 d7 c3 ff 48 8b 85 28 ff ff ff 4d 89 f1 4c 89 e9 4c 89 e2 48 89 de 48 c7 c7 c0 a1 11 85 49 89 c0 e8 33 e3 ad ff <0f> 0b 48 c7 c0 80 9f 11 85 eb 96 48 c7 c0 c0 9f 11 85 eb 8d 48 
RIP: report_usercopy mm/usercopy.c:76 [inline] RSP: ffff8801d1e6f148
RIP: __check_object_size+0x3a2/0x4f0 mm/usercopy.c:276 RSP: ffff8801d1e6f148
---[ end trace 9c15fa17a99c2fd6 ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..