[issue19636] Fix usage of MAX_PATH in posixmodule.c
Changes by STINNER Victor victor.stin...@gmail.com: -- resolution: - fixed status: open - closed versions: +Python 3.4 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19636 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19636] Fix usage of MAX_PATH in posixmodule.c
Roundup Robot added the comment: New changeset b3eb42a657a3 by Victor Stinner in branch 'default': Issue #19636: Fix posix__getvolumepathname(), raise an OverflowError if http://hg.python.org/cpython/rev/b3eb42a657a3 New changeset 46aecfc5e374 by Victor Stinner in branch 'default': Issue #19636: Fix usage of MAX_PATH in posixmodule.c http://hg.python.org/cpython/rev/46aecfc5e374 -- nosy: +python-dev ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19636 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19636] Fix usage of MAX_PATH in posixmodule.c
Tim Golden added the comment: Fine with your volumepathname patch. The core of the code was contributed and I didn't check it too carefully as it clearly worked. (For some definition of worked). -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19636 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19636] Fix usage of MAX_PATH in posixmodule.c
New submission from STINNER Victor: The length of a path is not always correctly handled in posixmodule.c, the worst case is posix__getvolumepathname() which pass a length two times smaller than the buffer (GetVolumePathNameW() expects a number of WCHAR characters, not a number of bytes). MAX_PATH includes the final null character, so no need to write MAX_PATH+1, especially when the function supports path longer than MAX_PATH-1 wide characters by allocating a larget buffer. http://msdn.microsoft.com/en-us/library/aa365247%28VS.85%29.aspx Maximum Path Length Limitation In the Windows API (with some exceptions discussed in the following paragraphs), the maximum length for a path is MAX_PATH, which is defined as 260 characters. A local path is structured in the following order: drive letter, colon, backslash, name components separated by backslashes, and a terminating null character. For example, the maximum path on drive D is D:\some 256-character path stringNUL where NUL represents the invisible terminating null character for the current system codepage. (The characters are used here for visual clarity and cannot be part of a valid path string.) Attached patch fixes usage of MAX_PATH in posixmodule.c. -- files: win_max_path.patch keywords: patch messages: 203231 nosy: haypo priority: normal severity: normal status: open title: Fix usage of MAX_PATH in posixmodule.c Added file: http://bugs.python.org/file32675/win_max_path.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19636 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19636] Fix usage of MAX_PATH in posixmodule.c
STINNER Victor added the comment:
posix__getfullpathname():
-char outbuf[MAX_PATH*2];
+char outbuf[MAX_PATH];
...
-wchar_t woutbuf[MAX_PATH*2], *woutbufp = woutbuf;
+wchar_t woutbuf[MAX_PATH], *woutbufp = woutbuf;
I don't know what *2 was used here, probably a mistake with
sizeof(wchar_t)=2? (try to allocate bytes, where the length is a number of wide
characters)
posix__getvolumepathname() is new in Python 3.4, so not need to backport its
fix.
path_converter():
length = PyBytes_GET_SIZE(bytes);
#ifdef MS_WINDOWS
-if (length MAX_PATH) {
+if (length MAX_PATH-1) {
FORMAT_EXCEPTION(PyExc_ValueError, %s too long for Windows);
Py_DECREF(bytes);
return 0;
I don't know if this fix should be backported to Python 3.3.
--
components: +Windows
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[issue19636] Fix usage of MAX_PATH in posixmodule.c
Changes by STINNER Victor victor.stin...@gmail.com: -- nosy: +tim.golden ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19636 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue19636] Fix usage of MAX_PATH in posixmodule.c
STINNER Victor added the comment: Oh, I forgot to mention that my initial concern was the following warning: ..\Modules\posixmodule.c(4057): warning C4267: 'function' : conversion from 'size_t' to 'DWORD', possible loss of data [C:\buildbot.python.org\3.x.kloth-win64\build\PCbuild\pythoncore.vcxproj] bufsize (Py_ssize_t) is passed to GetVolumePathNameW() which expected a DWORD. An OverflowError must be raised if bufsize is larger than DWORD_MAX (the constant is defined in Modules/_winapi.c, not in posixmodule.c). But I prefer to fix the warning after this issue. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue19636 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
