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| author | Sam Ezeh <sam.z.ezeh@gmail.com> | 2022-05-23 17:59:21 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-05-23 17:59:21 (GMT) |
| commit | 202ed2506c84cd98e9e35621b5b2929ceb717864 (patch) | |
| tree | 109cc1dc878a5380086cc782b81fb91cfdc1ce51 | |
| parent | 6a6f823ea7f565722148462a0372aa90085637bc (diff) | |
| download | cpython-202ed2506c84cd98e9e35621b5b2929ceb717864.zip cpython-202ed2506c84cd98e9e35621b5b2929ceb717864.tar.gz cpython-202ed2506c84cd98e9e35621b5b2929ceb717864.tar.bz2 | |
gh-83245: Raise BadZipFile instead of ValueError when reading a corrupt ZIP file (GH-32291)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
| -rw-r--r-- | Lib/test/test_zipfile.py | 11 | ||||
| -rw-r--r-- | Lib/zipfile.py | 2 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2022-04-03-19-40-09.bpo-39064.76PbIz.rst | 2 |
3 files changed, 15 insertions, 0 deletions
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py index 848bf4f..f4c11d8 100644 --- a/Lib/test/test_zipfile.py +++ b/Lib/test/test_zipfile.py @@ -1740,6 +1740,17 @@ class OtherTests(unittest.TestCase): fp.write("short file") self.assertRaises(zipfile.BadZipFile, zipfile.ZipFile, TESTFN) + def test_negative_central_directory_offset_raises_BadZipFile(self): + # Zip file containing an empty EOCD record + buffer = bytearray(b'PK\x05\x06' + b'\0'*18) + + # Set the size of the central directory bytes to become 1, + # causing the central directory offset to become negative + for dirsize in 1, 2**32-1: + buffer[12:16] = struct.pack('<L', dirsize) + f = io.BytesIO(buffer) + self.assertRaises(zipfile.BadZipFile, zipfile.ZipFile, f) + def test_closed_zip_raises_ValueError(self): """Verify that testzip() doesn't swallow inappropriate exceptions.""" data = io.BytesIO() diff --git a/Lib/zipfile.py b/Lib/zipfile.py index 9f44375..fc6ca65 100644 --- a/Lib/zipfile.py +++ b/Lib/zipfile.py @@ -1381,6 +1381,8 @@ class ZipFile: print("given, inferred, offset", offset_cd, inferred, concat) # self.start_dir: Position of start of central directory self.start_dir = offset_cd + concat + if self.start_dir < 0: + raise BadZipFile("Bad offset for central directory") fp.seek(self.start_dir, 0) data = fp.read(size_cd) fp = io.BytesIO(data) diff --git a/Misc/NEWS.d/next/Library/2022-04-03-19-40-09.bpo-39064.76PbIz.rst b/Misc/NEWS.d/next/Library/2022-04-03-19-40-09.bpo-39064.76PbIz.rst new file mode 100644 index 0000000..34d3152 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2022-04-03-19-40-09.bpo-39064.76PbIz.rst @@ -0,0 +1,2 @@ +:class:`zipfile.ZipFile` now raises :exc:`zipfile.BadZipFile` instead of ``ValueError`` when reading a +corrupt zip file in which the central directory offset is negative. |