Issue #29392: Prevent crash when passing invalid arguments into msvcrt module.

1 files changed, 19 insertions, 30 deletions

diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 919cf502dc..6854a44e2d 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -9,6 +9,9 @@
 #ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
+#ifdef HAVE_IO_H
+#include <io.h>
+#endif
 #ifdef HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
@@ -92,8 +95,7 @@ fileio_dealloc_warn(fileio *self, PyObject *source)
     if (self->fd >= 0 && self->closefd) {
         PyObject *exc, *val, *tb;
         PyErr_Fetch(&exc, &val, &tb);
-        if (PyErr_WarnFormat(PyExc_ResourceWarning, 1,
-                             "unclosed file %R", source)) {
+        if (PyErr_ResourceWarning(source, 1, "unclosed file %R", source)) {
             /* Spurious errors can appear at shutdown */
             if (PyErr_ExceptionMatches(PyExc_Warning))
                 PyErr_WriteUnraisable((PyObject *) self);
@@ -118,18 +120,13 @@ internal_close(fileio *self)
         int fd = self->fd;
         self->fd = -1;
         /* fd is accessible and someone else may have closed it */
-        if (_PyVerify_fd(fd)) {
-            Py_BEGIN_ALLOW_THREADS
-            _Py_BEGIN_SUPPRESS_IPH
-            err = close(fd);
-            if (err < 0)
-                save_errno = errno;
-            _Py_END_SUPPRESS_IPH
-            Py_END_ALLOW_THREADS
-        } else {
+        Py_BEGIN_ALLOW_THREADS
+        _Py_BEGIN_SUPPRESS_IPH
+        err = close(fd);
+        if (err < 0)
             save_errno = errno;
-            err = -1;
-        }
+        _Py_END_SUPPRESS_IPH
+        Py_END_ALLOW_THREADS
     }
     if (err < 0) {
         errno = save_errno;
@@ -546,7 +543,7 @@ err_closed(void)
 }
 
 static PyObject *
-err_mode(char *action)
+err_mode(const char *action)
 {
     _PyIO_State *state = IO_STATE();
     if (state != NULL)
@@ -701,8 +698,6 @@ _io_FileIO_readall_impl(fileio *self)
 
     if (self->fd < 0)
         return err_closed();
-    if (!_PyVerify_fd(self->fd))
-        return PyErr_SetFromErrno(PyExc_IOError);
 
     _Py_BEGIN_SUPPRESS_IPH
 #ifdef MS_WINDOWS
@@ -915,18 +910,15 @@ portable_lseek(int fd, PyObject *posobj, int whence)
             return NULL;
     }
 
-    if (_PyVerify_fd(fd)) {
-        Py_BEGIN_ALLOW_THREADS
-        _Py_BEGIN_SUPPRESS_IPH
+    Py_BEGIN_ALLOW_THREADS
+    _Py_BEGIN_SUPPRESS_IPH
 #ifdef MS_WINDOWS
-        res = _lseeki64(fd, pos, whence);
+    res = _lseeki64(fd, pos, whence);
 #else
-        res = lseek(fd, pos, whence);
+    res = lseek(fd, pos, whence);
 #endif
-        _Py_END_SUPPRESS_IPH
-        Py_END_ALLOW_THREADS
-    } else
-        res = -1;
+    _Py_END_SUPPRESS_IPH
+    Py_END_ALLOW_THREADS
     if (res < 0)
         return PyErr_SetFromErrno(PyExc_IOError);
 
@@ -1049,7 +1041,7 @@ _io_FileIO_truncate_impl(fileio *self, PyObject *posobj)
 }
 #endif /* HAVE_FTRUNCATE */
 
-static char *
+static const char *
 mode_string(fileio *self)
 {
     if (self->created) {
@@ -1117,10 +1109,7 @@ _io_FileIO_isatty_impl(fileio *self)
         return err_closed();
     Py_BEGIN_ALLOW_THREADS
     _Py_BEGIN_SUPPRESS_IPH
-    if (_PyVerify_fd(self->fd))
-        res = isatty(self->fd);
-    else
-        res = 0;
+    res = isatty(self->fd);
     _Py_END_SUPPRESS_IPH
     Py_END_ALLOW_THREADS
     return PyBool_FromLong(res);