lib-compression: Fix length checks for zlib header

diff --git a/src/lib-compression/istream-zlib.c b/src/lib-compression/istream-zlib.c
index 3e514cab84267090f7a09e59414b0dbbf333bcf8..c04df039d8f68bbd7b95ac43b7afbe1ad55d47fb 100644 (file)
--- a/src/lib-compression/istream-zlib.c
+++ b/src/lib-compression/istream-zlib.c
@@ -100,12 +100,12 @@ static int i_stream_zlib_read_header(struct istream_private *stream)
                return -1;
        }
        if ((data[3] & GZ_FLAG_FEXTRA) != 0) {
-               if (pos + 2 < size)
+               if (pos + 2 > size)
                        return 0;
 
                fextra_size = le16_to_cpu_unaligned(&data[pos]);
                pos += 2;
-               if (pos + fextra_size < size)
+               if (pos + fextra_size > size)
                        return 0;
                pos += fextra_size;
        }
@@ -122,7 +122,7 @@ static int i_stream_zlib_read_header(struct istream_private *stream)
                } while (data[pos++] != '\0');
        }
        if ((data[3] & GZ_FLAG_FHCRC) != 0) {
-               if (pos + 2 < size)
+               if (pos + 2 > size)
                        return 0;
                pos += 2;
        }