From e834e786a5997f5f4bfdf4686bbd560133d88faa Mon Sep 17 00:00:00 2001 From: Bruno Almeida Date: Mon, 31 Jul 2023 08:24:06 +0100 Subject: [PATCH 1/3] gh-107396: tarfiles: set self.exception before _init_read_gz() In the stack call of: _init_read_gz() ``` _read, tarfile.py:548 read, tarfile.py:526 _init_read_gz, tarfile.py:491 ``` a try;except exists that uses `self.exception`, so it needs to be set before calling _init_read_gz(). closes: #107396 --- Lib/tarfile.py | 2 +- Lib/test/test_tarfile.py | 17 +++++++++++++++++ 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/Lib/tarfile.py b/Lib/tarfile.py index df4e41f7a0d23a..54293949e88fd1 100755 --- a/Lib/tarfile.py +++ b/Lib/tarfile.py @@ -372,8 +372,8 @@ def __init__(self, name, mode, comptype, fileobj, bufsize, self.zlib = zlib self.crc = zlib.crc32(b"") if mode == "r": - self._init_read_gz() self.exception = zlib.error + self._init_read_gz() else: self._init_write_gz(compresslevel) diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py index 2eda7fc4ceac71..d646611c331720 100644 --- a/Lib/test/test_tarfile.py +++ b/Lib/test/test_tarfile.py @@ -938,6 +938,23 @@ class LzmaDetectReadTest(LzmaTest, DetectReadTest): pass +class GzipBrokenHeaderCorrectException(GzipTest, unittest.TestCase): + """ + See: https://github.com/python/cpython/issues/107396 + """ + def runTest(self): + f = io.BytesIO( + b'\x1f\x8b' # header + b'\x08' # compression method + b'\x04' # flags + b'\0\0\0\0\0\0' # padding? + b'\0\x01' # size + b'\0\0\0\0\0' # corrupt data (zeros) + ) + with self.assertRaises(tarfile.ReadError): + tarfile.open(fileobj=f, mode='r|gz') + + class MemberReadTest(ReadTest, unittest.TestCase): def _test_member(self, tarinfo, chksum=None, **kwargs): From 25ac1e4b4761e80704e7746421ccf3f0a868f014 Mon Sep 17 00:00:00 2001 From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com> Date: Mon, 31 Jul 2023 07:36:25 +0000 Subject: [PATCH 2/3] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?= =?UTF-8?q?rb=5Fit.?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../next/Library/2023-07-31-07-36-24.gh-issue-107396.3_Kh6D.rst | 1 + 1 file changed, 1 insertion(+) create mode 100644 Misc/NEWS.d/next/Library/2023-07-31-07-36-24.gh-issue-107396.3_Kh6D.rst diff --git a/Misc/NEWS.d/next/Library/2023-07-31-07-36-24.gh-issue-107396.3_Kh6D.rst b/Misc/NEWS.d/next/Library/2023-07-31-07-36-24.gh-issue-107396.3_Kh6D.rst new file mode 100644 index 00000000000000..73bff4bdbe024d --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-07-31-07-36-24.gh-issue-107396.3_Kh6D.rst @@ -0,0 +1 @@ +tarfiles; Fixed use before assignment of self.exception for gzip decompression From 0993b5b9c61d01b9ba330db9088fcb1eacc01766 Mon Sep 17 00:00:00 2001 From: Petr Viktorin Date: Mon, 21 Aug 2023 12:03:36 +0200 Subject: [PATCH 3/3] Update comment --- Lib/test/test_tarfile.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py index d646611c331720..02abc07183eb5c 100644 --- a/Lib/test/test_tarfile.py +++ b/Lib/test/test_tarfile.py @@ -947,7 +947,7 @@ def runTest(self): b'\x1f\x8b' # header b'\x08' # compression method b'\x04' # flags - b'\0\0\0\0\0\0' # padding? + b'\0\0\0\0\0\0' # timestamp, compression data, OS ID b'\0\x01' # size b'\0\0\0\0\0' # corrupt data (zeros) )