diff --git a/Lib/tarfile.py b/Lib/tarfile.py index 1d15612616f1d8..043a4ab5a52a6f 100755 --- a/Lib/tarfile.py +++ b/Lib/tarfile.py @@ -2345,6 +2345,15 @@ def next(self): raise ReadError(str(e)) except SubsequentHeaderError as e: raise ReadError(str(e)) + except Exception as e: + try: + import zlib + if isinstance(e, zlib.error): + raise ReadError(f'zlib error: {e}') + else: + raise e + except ImportError: + raise e break if tarinfo is not None: diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py index 6279309ed3bf1f..06fb97212d8567 100644 --- a/Lib/test/test_tarfile.py +++ b/Lib/test/test_tarfile.py @@ -18,6 +18,10 @@ import gzip except ImportError: gzip = None +try: + import zlib +except ImportError: + zlib = None try: import bz2 except ImportError: @@ -686,6 +690,16 @@ def test_parallel_iteration(self): self.assertEqual(m1.offset, m2.offset) self.assertEqual(m1.get_info(), m2.get_info()) + @unittest.skipIf(zlib is None, "requires zlib") + def test_zlib_error_does_not_leak(self): + # bpo-39039: tarfile.open allowed zlib exceptions to bubble up when + # parsing certain types of invalid data + with unittest.mock.patch("tarfile.TarInfo.fromtarfile") as mock: + mock.side_effect = zlib.error + with self.assertRaises(tarfile.ReadError): + tarfile.open(self.tarname) + + class MiscReadTest(MiscReadTestBase, unittest.TestCase): test_fail_comp = None diff --git a/Misc/NEWS.d/next/Library/2021-08-18-10-36-14.bpo-39039.A63LYh.rst b/Misc/NEWS.d/next/Library/2021-08-18-10-36-14.bpo-39039.A63LYh.rst new file mode 100644 index 00000000000000..7250055c2a4a9e --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-08-18-10-36-14.bpo-39039.A63LYh.rst @@ -0,0 +1,2 @@ +tarfile.open raises :exc:`~tarfile.ReadError` when a zlib error occurs +during file extraction.