https://github.com/python/cpython/commit/80c84641253a0562896667ffd1ba483c4e86a9fc commit: 80c84641253a0562896667ffd1ba483c4e86a9fc branch: 3.14 author: Victor Stinner <[email protected]> committer: vstinner <[email protected]> date: 2026-10-16T23:08:02Z summary:
[3.14] gh-133998: Fix gzip file creation when time is out of range (#159592) [3.15] gh-133998: Fix gzip file creation when time is out of range (GH-134278) (GH-150221) (cherry picked from commit 1daad8a1630c9ee011f6ff3796c4e7aef243463b) (cherry picked from commit b039d1bd976819320af15494a11c973e0eca02f1) Co-authored-by: Miss Islington (bot) <[email protected]> Co-authored-by: adang1345 <[email protected]> Co-authored-by: Serhiy Storchaka <[email protected]> files: A Misc/NEWS.d/next/Library/2025-05-19-20-29-35.gh-issue-133998.KmElUw.rst M Doc/library/gzip.rst M Lib/gzip.py M Lib/test/test_gzip.py diff --git a/Doc/library/gzip.rst b/Doc/library/gzip.rst index a3c98d2f42b0b1..a370ab5629041b 100644 --- a/Doc/library/gzip.rst +++ b/Doc/library/gzip.rst @@ -103,9 +103,13 @@ The module defines the following items: is no compression. The default is ``9``. The optional *mtime* argument is the timestamp requested by gzip. The time - is in Unix format, i.e., seconds since 00:00:00 UTC, January 1, 1970. - If *mtime* is omitted or ``None``, the current time is used. Use *mtime* = 0 - to generate a compressed stream that does not depend on creation time. + is in Unix format, i.e., seconds since 00:00:00 UTC, January 1, 1970. Set + *mtime* to ``0`` to generate a compressed stream that does not depend on + creation time. If *mtime* is omitted or ``None``, the current time is used; + however, if the current time is outside the range 00:00:00 UTC, January 1, + 1970 through 06:28:15 UTC, February 7, 2106, or explicitly passed *mtime* + argument is outside the range ``0`` to ``2**32-1``, then the value ``0`` + is used instead. See below for the :attr:`mtime` attribute that is set when decompressing. diff --git a/Lib/gzip.py b/Lib/gzip.py index f3f9fa91c8161b..4dec70c54b2d46 100644 --- a/Lib/gzip.py +++ b/Lib/gzip.py @@ -189,9 +189,10 @@ def __init__(self, filename=None, mode=None, The optional mtime argument is the timestamp requested by gzip. The time is in Unix format, i.e., seconds since 00:00:00 UTC, - January 1, 1970. If mtime is omitted or None, the current time - is used. Use mtime = 0 to generate a compressed stream that does - not depend on creation time. + January 1, 1970. Set mtime to 0 to generate a compressed stream + that does not depend on creation time. If mtime is omitted or None, + the current time is used. If the resulting mtime is outside the + range 0 to 2**32-1, then the value 0 is used instead. """ @@ -299,6 +300,8 @@ def _write_gzip_header(self, compresslevel): mtime = self._write_mtime if mtime is None: mtime = time.time() + if not 0 <= mtime < 2**32: + mtime = 0 write32u(self.fileobj, int(mtime)) if compresslevel == _COMPRESS_LEVEL_BEST: xfl = b'\002' @@ -634,6 +637,8 @@ def compress(data, compresslevel=_COMPRESS_LEVEL_BEST, *, mtime=0): gzip_data = zlib.compress(data, level=compresslevel, wbits=31) if mtime is None: mtime = time.time() + if not 0 <= mtime < 2**32: + mtime = 0 # Reuse gzip header created by zlib, replace mtime and OS byte for # consistency. header = struct.pack("<4sLBB", gzip_data, int(mtime), gzip_data[8], 255) diff --git a/Lib/test/test_gzip.py b/Lib/test/test_gzip.py index ccbacc7c19b6e6..fc61eddd827a51 100644 --- a/Lib/test/test_gzip.py +++ b/Lib/test/test_gzip.py @@ -11,6 +11,7 @@ import unittest import warnings from subprocess import PIPE, Popen +from unittest import mock from test.support import catch_unraisable_exception from test.support import import_helper from test.support import os_helper @@ -351,6 +352,26 @@ def test_mtime(self): self.assertEqual(dataRead, data1) self.assertEqual(fRead.mtime, mtime) + def test_mtime_out_of_range(self): + for mtime in (-1, 2**32): + with gzip.GzipFile(self.filename, 'w', mtime=mtime) as fWrite: + fWrite.write(data1) + with gzip.GzipFile(self.filename) as fRead: + fRead.read(1) + self.assertEqual(fRead.mtime, 0) + datac = gzip.compress(data1, mtime=mtime) + with gzip.GzipFile(fileobj=io.BytesIO(datac)) as fRead: + fRead.read(1) + self.assertEqual(fRead.mtime, 0) + + for mtime in (-1, 2**32): + with mock.patch('time.time', return_value=float(mtime)): + with gzip.GzipFile(self.filename, 'w') as fWrite: + fWrite.write(data1) + with gzip.GzipFile(self.filename) as fRead: + fRead.read(1) + self.assertEqual(fRead.mtime, 0) + def test_metadata(self): mtime = 123456789 diff --git a/Misc/NEWS.d/next/Library/2025-05-19-20-29-35.gh-issue-133998.KmElUw.rst b/Misc/NEWS.d/next/Library/2025-05-19-20-29-35.gh-issue-133998.KmElUw.rst new file mode 100644 index 00000000000000..77d92628beefac --- /dev/null +++ b/Misc/NEWS.d/next/Library/2025-05-19-20-29-35.gh-issue-133998.KmElUw.rst @@ -0,0 +1,5 @@ +Fix :exc:`struct.error` exception when creating a file with +:class:`gzip.GzipFile` or compressing data with :func:`gzip.compress` +if the system time is outside the range 00:00:00 UTC, January 1, 1970 +through 06:28:15 UTC, February 7, 2106, or explicitly passed *mtime* +argument is outside the range ``0`` to ``2**32-1``. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
