Fix BZ #17269 -- _IO_wstr_overflow integer overflow

(cherry picked from commit bdf1ff052a8e23d637f2c838fa5642d78fcedc33)
(cherry picked from commit 8a4e5cc6574a419d5724bef6be98d705d58db48d)

diff --git a/libio/wstrops.c b/libio/wstrops.c
index 43d847d034af95fd7e8ca5c01798ed60f3bfa194..3993579bd144bc1a0dff50ca65469a9f1f29aa8c 100644 (file)
--- a/libio/wstrops.c
+++ b/libio/wstrops.c
@@ -95,8 +95,11 @@ _IO_wstr_overflow (fp, c)
          wchar_t *old_buf = fp->_wide_data->_IO_buf_base;
          size_t old_wblen = _IO_wblen (fp);
          _IO_size_t new_size = 2 * old_wblen + 100;
-         if (new_size < old_wblen)
+
+         if (__glibc_unlikely (new_size < old_wblen)
+             || __glibc_unlikely (new_size > SIZE_MAX / sizeof (wchar_t)))
            return EOF;
+
          new_buf
            = (wchar_t *) (*((_IO_strfile *) fp)->_s._allocate_buffer) (new_size
                                                                        * sizeof (wchar_t));
@@ -186,6 +189,9 @@ enlarge_userbuf (_IO_FILE *fp, _IO_off64_t offset, int reading)
     return 1;
 
   _IO_size_t newsize = offset + 100;
+  if (__glibc_unlikely (newsize > SIZE_MAX / sizeof (wchar_t)))
+    return 1;
+
   wchar_t *oldbuf = wd->_IO_buf_base;
   wchar_t *newbuf
     = (wchar_t *) (*((_IO_strfile *) fp)->_s._allocate_buffer) (newsize