bpo-23224: Fix segfaults and multiple leaks in the lzma and bz2 modules (GH-7822)

lzma.LZMADecompressor and bz2.BZ2Decompressor objects caused
segfaults when their `__init__()` methods were not called.

lzma.LZMADecompressor, lzma.LZMACompressor, bz2.BZ2Compressor,
and bz2.BZ2Decompressor objects would leak locks and internal buffers
when their `__init__()` methods were called multiple times.


https://bugs.python.org/issue23224

2 files changed, 8 insertions, 0 deletions

diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index c97ed1c..e4dd7fc 100644
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -844,6 +844,10 @@ class BZ2DecompressorTest(BaseTest):
             bzd.__init__()
         self.assertAlmostEqual(gettotalrefcount() - refs_before, 0, delta=10)
 
+    def test_uninitialized_BZ2Decompressor_crash(self):
+        self.assertEqual(BZ2Decompressor.__new__(BZ2Decompressor).
+                         decompress(bytes()), b'')
+
 
 class CompressDecompressTest(BaseTest):
     def testCompress(self):
diff --git a/Lib/test/test_lzma.py b/Lib/test/test_lzma.py
index 18f474b..ac53bdd 100644
--- a/Lib/test/test_lzma.py
+++ b/Lib/test/test_lzma.py
@@ -380,6 +380,10 @@ class CompressorDecompressorTestCase(unittest.TestCase):
             lzd.__init__()
         self.assertAlmostEqual(gettotalrefcount() - refs_before, 0, delta=10)
 
+    def test_uninitialized_LZMADecompressor_crash(self):
+        self.assertEqual(LZMADecompressor.__new__(LZMADecompressor).
+                         decompress(bytes()), b'')
+
 
 class CompressDecompressFunctionTestCase(unittest.TestCase):