[Python-checkins] cpython (merge 3.3 -> default): Issue #20078: Reading malformed zipfiles no longer hangs with 100% CPU

Thu Jan 9 13:54:27 CET 2014

http://hg.python.org/cpython/rev/79ea4ce431b1
changeset: 88364:79ea4ce431b1
parent: 88362:9e3f5b5bcf7e
parent: 88363:0cf1defd5ac4
user: Serhiy Storchaka <storchaka at gmail.com>
date: Thu Jan 09 14:53:41 2014 +0200
summary:
 Issue #20078: Reading malformed zipfiles no longer hangs with 100% CPU
consumption.
files:
 Lib/test/test_zipfile.py | 31 ++++++++++++++++++++++++++++
 Lib/zipfile.py | 2 +
 Misc/NEWS | 3 ++
 3 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -297,6 +297,36 @@
 buf = fp.read(test_size)
 self.assertEqual(len(buf), test_size)
 
+ def test_truncated_zipfile(self):
+ fp = io.BytesIO()
+ with zipfile.ZipFile(fp, mode='w') as zipf:
+ zipf.writestr('strfile', self.data, compress_type=self.compression)
+ end_offset = fp.tell()
+ zipfiledata = fp.getvalue()
+
+ fp = io.BytesIO(zipfiledata)
+ with zipfile.ZipFile(fp) as zipf:
+ with zipf.open('strfile') as zipopen:
+ fp.truncate(end_offset - 20)
+ with self.assertRaises(EOFError):
+ zipopen.read()
+
+ fp = io.BytesIO(zipfiledata)
+ with zipfile.ZipFile(fp) as zipf:
+ with zipf.open('strfile') as zipopen:
+ fp.truncate(end_offset - 20)
+ with self.assertRaises(EOFError):
+ while zipopen.read(100):
+ pass
+
+ fp = io.BytesIO(zipfiledata)
+ with zipfile.ZipFile(fp) as zipf:
+ with zipf.open('strfile') as zipopen:
+ fp.truncate(end_offset - 20)
+ with self.assertRaises(EOFError):
+ while zipopen.read1(100):
+ pass
+
 def tearDown(self):
 unlink(TESTFN)
 unlink(TESTFN2)
@@ -393,6 +423,7 @@
 with zipfile.ZipFile(TESTFN2, "w") as zipfp:
 self.assertRaises(ValueError, zipfp.write, TESTFN)
 
+
 @requires_zlib
 class DeflateTestsWithSourceFile(AbstractTestsWithSourceFile,
 unittest.TestCase):
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -862,6 +862,8 @@
 
 data = self._fileobj.read(n)
 self._compress_left -= len(data)
+ if not data:
+ raise EOFError
 
 if self._decrypter is not None:
 data = bytes(map(self._decrypter, data))
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -18,6 +18,9 @@
 Library
 -------
 
+- Issue #20078: Reading malformed zipfiles no longer hangs with 100% CPU
+ consumption.
+
 - Issue #20113: os.readv() and os.writev() now raise an OSError exception on
 error instead of returning -1.
 
-- 
Repository URL: http://hg.python.org/cpython
