changeset 88364:79ea4ce431b1

Issue #20078: Reading malformed zipfiles no longer hangs with 100% CPU consumption. [#20078]
author Serhiy Storchaka <storchaka@gmail.com>
date Thu, 09 Jan 2014 14:53:41 +0200
parents 9e3f5b5bcf7e (current diff) 0cf1defd5ac4 (diff)
children a1a5c4274c1c
files Lib/test/test_zipfile.py Lib/zipfile.py Misc/NEWS
diffstat 3 files changed, 36 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -297,6 +297,36 @@ class AbstractTestsWithSourceFile:
                     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 @@ class StoredTestsWithSourceFile(Abstract
         with zipfile.ZipFile(TESTFN2, "w") as zipfp:
             self.assertRaises(ValueError, zipfp.write, TESTFN)
 
+
 @requires_zlib
 class DeflateTestsWithSourceFile(AbstractTestsWithSourceFile,
                                  unittest.TestCase):
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -862,6 +862,8 @@ class ZipExtFile(io.BufferedIOBase):
 
         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))
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -18,6 +18,9 @@ Core and Builtins
 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.