Decompressors: check for write errors in decompress_unlzo.c

The return value of flush() is not checked in unlzo().  This means that
the decompressor won't stop even if the caller doesn't want more data.
This can happen e.g.  with a corrupt LZO-compressed initramfs image.
Signed-off-by: NLasse Collin <lasse.collin@tukaani.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lib/decompress_unlzo.c

@@ -187,8 +187,8 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
 			}
 		}
 
-		if (flush)
-			flush(out_buf, dst_len);
+		if (flush && flush(out_buf, dst_len) != dst_len)
+			goto exit_2;
 		if (output)
 			out_buf += dst_len;
 		if (posp)