[bzip2, gzip] Avoid access of unitialized memory (#46109).

* src/bzip2/ftbzip2.c (ft_bzip2_file_fill_output), src/gzip/ftgzip.c
(ft_gzip_file_fill_output): In case of an error, adjust the limit to
avoid copying uninitialized memory.

ChangeLog

@@ -1,3 +1,11 @@
+2015-10-03  Werner Lemberg  <wl@gnu.org>
+
+	[bzip2, gzip] Avoid access of unitialized memory (#46109).
+
+	* src/bzip2/ftbzip2.c (ft_bzip2_file_fill_output), src/gzip/ftgzip.c
+	(ft_gzip_file_fill_output): In case of an error, adjust the limit to
+	avoid copying uninitialized memory.
+
 2015-10-01  Alexei Podtelezhnikov  <apodtele@gmail.com>
 
 	[smooth] Clean up worker.

src/bzip2/ftbzip2.c

@@ -310,7 +310,8 @@
       }
       else if ( err != BZ_OK )
       {
-        error = FT_THROW( Invalid_Stream_Operation );
+        zip->limit = zip->cursor;
+        error      = FT_THROW( Invalid_Stream_Operation );
         break;
       }
     }

src/gzip/ftgzip.c

@@ -433,7 +433,8 @@
       }
       else if ( err != Z_OK )
       {
-        error = FT_THROW( Invalid_Stream_Operation );
+        zip->limit = zip->cursor;
+        error      = FT_THROW( Invalid_Stream_Operation );
         break;
       }
     }