usercopy: kernel memory overwrite attempt detected to ffff8801d21c9bd4 (kvm_vcpu) (1320 bytes) ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:84! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 2988 Comm: syzkaller562838 Not tainted 4.14.0-rc5-next-20171018+ #36 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d1da0100 task.stack: ffff8801d1c30000 RIP: 0010:report_usercopy mm/usercopy.c:76 [inline] RIP: 0010:__check_object_size+0x3a2/0x4f0 mm/usercopy.c:276 RSP: 0018:ffff8801d1c37148 EFLAGS: 00010286 RAX: 000000000000005e RBX: ffffffff8511a0e0 RCX: 0000000000000000 RDX: 000000000000005e RSI: 1ffff1003a386de9 RDI: ffffed003a386e1d RBP: ffff8801d1c37238 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8511a0a0 R13: ffff8801d21c9bd4 R14: 0000000000000528 R15: ffffea0007487200 FS: 0000000000964880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020ae6fe8 CR3: 00000001d2184000 CR4: 00000000001426e0 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: 0033:0x442f27 RSP: 002b:00007ffc7f9721b8 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffc7f972890 RCX: 0000000000442f27 RDX: 00007ffc7f972890 RSI: 000000004008ae90 RDI: 0000000000000005 RBP: 0000000000000082 R08: 0000000000000001 R09: ffffffffffffffff R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000404040 R13: 00000000004040d0 R14: 0000000000000000 R15: 0000000000000000 Code: 48 0f 44 da e8 70 f0 c3 ff 48 8b 85 28 ff ff ff 4d 89 f1 4c 89 e9 4c 89 e2 48 89 de 48 c7 c7 a0 a1 11 85 49 89 c0 e8 c3 fb ad ff <0f> 0b 48 c7 c0 60 9f 11 85 eb 96 48 c7 c0 a0 9f 11 85 eb 8d 48 RIP: report_usercopy mm/usercopy.c:76 [inline] RSP: ffff8801d1c37148 RIP: __check_object_size+0x3a2/0x4f0 mm/usercopy.c:276 RSP: ffff8801d1c37148 ---[ end trace d80029d430f95081 ]--- Kernel panic - not syncing: Fatal exception Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..