diff --git a/vendor/golang.org/x/sys/windows/security_windows.go b/vendor/golang.org/x/sys/windows/security_windows.go
index c605ee6..9e3c44a 100644
--- a/vendor/golang.org/x/sys/windows/security_windows.go
+++ b/vendor/golang.org/x/sys/windows/security_windows.go
@@ -7,6 +7,8 @@
 import (
 	"syscall"
 	"unsafe"
+
+	"golang.org/x/sys/internal/unsafeheader"
 )
 
 const (
@@ -235,7 +237,7 @@
 		return ""
 	}
 	defer LocalFree((Handle)(unsafe.Pointer(s)))
-	return UTF16ToString((*[(1 << 30) - 1]uint16)(unsafe.Pointer(s))[:])
+	return UTF16ToString((*[256]uint16)(unsafe.Pointer(s))[:])
 }
 
 // Len returns the length, in bytes, of a valid security identifier SID.
@@ -1229,7 +1231,7 @@
 		return ""
 	}
 	defer LocalFree(Handle(unsafe.Pointer(sddl)))
-	return UTF16ToString((*[(1 << 30) - 1]uint16)(unsafe.Pointer(sddl))[:])
+	return UTF16PtrToString(sddl)
 }
 
 // ToAbsolute converts a self-relative security descriptor into an absolute one.
@@ -1307,9 +1309,17 @@
 }
 
 func (selfRelativeSD *SECURITY_DESCRIPTOR) copySelfRelativeSecurityDescriptor() *SECURITY_DESCRIPTOR {
-	sdBytes := make([]byte, selfRelativeSD.Length())
-	copy(sdBytes, (*[(1 << 31) - 1]byte)(unsafe.Pointer(selfRelativeSD))[:len(sdBytes)])
-	return (*SECURITY_DESCRIPTOR)(unsafe.Pointer(&sdBytes[0]))
+	sdLen := (int)(selfRelativeSD.Length())
+
+	var src []byte
+	h := (*unsafeheader.Slice)(unsafe.Pointer(&src))
+	h.Data = unsafe.Pointer(selfRelativeSD)
+	h.Len = sdLen
+	h.Cap = sdLen
+
+	dst := make([]byte, sdLen)
+	copy(dst, src)
+	return (*SECURITY_DESCRIPTOR)(unsafe.Pointer(&dst[0]))
 }
 
 // SecurityDescriptorFromString converts an SDDL string describing a security descriptor into a
@@ -1391,6 +1401,6 @@
 	}
 	defer LocalFree(Handle(unsafe.Pointer(winHeapACL)))
 	aclBytes := make([]byte, winHeapACL.aclSize)
-	copy(aclBytes, (*[(1 << 31) - 1]byte)(unsafe.Pointer(winHeapACL))[:len(aclBytes)])
+	copy(aclBytes, (*[(1 << 31) - 1]byte)(unsafe.Pointer(winHeapACL))[:len(aclBytes):len(aclBytes)])
 	return (*ACL)(unsafe.Pointer(&aclBytes[0])), nil
 }