1 files changed, 12 insertions, 0 deletions
diff --git a/win32/win32.c b/win32/win32.c
index 5829e86d68..eb062f5c03 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -4316,6 +4316,10 @@ rb_w32_read(int fd, void *buf, size_t size)
     if (is_socket(sock))
 	return rb_w32_recv(fd, buf, size, 0);
 
+    // validate fd by using _get_osfhandle() because we cannot access _nhandle
+    if (_get_osfhandle(fd) == -1) {
+	return -1;
+    }
     if (!(_osfile(fd) & FOPEN)) {
 	errno = EBADF;
 	return -1;
@@ -4430,6 +4434,10 @@ rb_w32_write(int fd, const void *buf, size_t size)
     if (is_socket(sock))
 	return rb_w32_send(fd, buf, size, 0);
 
+    // validate fd by using _get_osfhandle() because we cannot access _nhandle
+    if (_get_osfhandle(fd) == -1) {
+	return -1;
+    }
     if (!(_osfile(fd) & FOPEN)) {
 	errno = EBADF;
 	return -1;
@@ -4682,6 +4690,10 @@ rb_w32_unlink(const char *path)
 int
 rb_w32_isatty(int fd)
 {
+    // validate fd by using _get_osfhandle() because we cannot access _nhandle
+    if (_get_osfhandle(fd) == -1) {
+	return 0;
+    }
     if (!(_osfile(fd) & FOPEN)) {
 	errno = EBADF;
 	return 0;