diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-03-02-13-49-21.gh-issue-102281.QCuu2N.rst b/Misc/NEWS.d/next/Core and Builtins/2023-03-02-13-49-21.gh-issue-102281.QCuu2N.rst new file mode 100644 index 00000000000000..b0269dd3d92bd5 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2023-03-02-13-49-21.gh-issue-102281.QCuu2N.rst @@ -0,0 +1 @@ +Fix potential nullptr dereference and use of uninitialized memory in fileutils. Patch by Max Bachmann. diff --git a/Modules/getpath.c b/Modules/getpath.c index 13db010649fed8..d17ddbfca9ab2d 100644 --- a/Modules/getpath.c +++ b/Modules/getpath.c @@ -447,7 +447,10 @@ getpath_realpath(PyObject *Py_UNUSED(self) , PyObject *args) if (s) { *s = L'\0'; } - path2 = _Py_normpath(_Py_join_relfile(path, resolved), -1); + path2 = _Py_join_relfile(path, resolved); + if (path2) { + path2 = _Py_normpath(path2, -1); + } PyMem_RawFree((void *)path); path = path2; } diff --git a/Python/fileutils.c b/Python/fileutils.c index 897c2f9f4ea160..1da6a6691f4271 100644 --- a/Python/fileutils.c +++ b/Python/fileutils.c @@ -2158,7 +2158,10 @@ _Py_join_relfile(const wchar_t *dirname, const wchar_t *relfile) } assert(wcslen(dirname) < MAXPATHLEN); assert(wcslen(relfile) < MAXPATHLEN - wcslen(dirname)); - join_relfile(filename, bufsize, dirname, relfile); + if (join_relfile(filename, bufsize, dirname, relfile) < 0) { + PyMem_RawFree(filename); + return NULL; + } return filename; } @@ -2196,6 +2199,7 @@ _Py_find_basename(const wchar_t *filename) wchar_t * _Py_normpath(wchar_t *path, Py_ssize_t size) { + assert(path != NULL); if (!path[0] || size == 0) { return path; }