From: Matthias Klose <doko@ubuntu.com>
Date: Sat, 4 Apr 2009 14:19:56 +0000 (+0000)
Subject: Merged revisions 71152 via svnmerge from
X-Git-Tag: v2.6.2c1~28
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a8da9e0e161ecf79703ae2a29f17619580166979;p=python

Merged revisions 71152 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r71152 | matthias.klose | 2009-04-04 16:18:13 +0200 (Sa, 04 Apr 2009) | 3 lines

  - Issue #3845: In PyRun_SimpleFileExFlags avoid invalid memory access with
    short file names.
........
---

diff --git a/Misc/NEWS b/Misc/NEWS
index edb2f4b2b4..09190a0b90 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -89,6 +89,9 @@ Core and Builtins
 - Issue #4509: Various issues surrounding resize of bytearray objects to
   which there are buffer exports.
 
+- Issue #3845: In PyRun_SimpleFileExFlags avoid invalid memory access with
+  short file names.
+
 Library
 -------
 
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 38db290ea7..977ee214d6 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -895,7 +895,7 @@ PyRun_SimpleFileExFlags(FILE *fp, const char *filename, int closeit,
 {
 	PyObject *m, *d, *v;
 	const char *ext;
-	int set_file_name = 0, ret;
+	int set_file_name = 0, ret, len;
 
 	m = PyImport_AddModule("__main__");
 	if (m == NULL)
@@ -912,7 +912,8 @@ PyRun_SimpleFileExFlags(FILE *fp, const char *filename, int closeit,
 		set_file_name = 1;
 		Py_DECREF(f);
 	}
-	ext = filename + strlen(filename) - 4;
+	len = strlen(filename);
+	ext = filename + len - (len > 4 ? 4 : 0);
 	if (maybe_pyc_file(fp, filename, ext, closeit)) {
 		/* Try to run a pyc file. First, re-open in binary */
 		if (closeit)