Fix reading harddisk serials.

It was falsely assumed that the harddisk serial is terminated
by NULL. This is not the case, so we initialize the memory
with zeros and copy only 20 bytes.

diff --git a/src/_fireinfo/fireinfo.c b/src/_fireinfo/fireinfo.c
index 4ab2bfad7083aa61275037c3d5b55cc36766626f..fc639d9d4cd904ec03e6a41e71313ce030098fe9 100644 (file)
--- a/src/_fireinfo/fireinfo.c
+++ b/src/_fireinfo/fireinfo.c
@@ -209,7 +209,9 @@ do_get_harddisk_serial(PyObject *o, PyObject *args) {
 
        if (!ioctl(fd, HDIO_GET_IDENTITY, &hd)) {
                char serial[21];
-               strncpy(serial, (const char *)hd.serial_no, sizeof(serial));
+               memset(serial, 0, sizeof(serial));
+
+               strncpy(serial, (const char *)hd.serial_no, sizeof(serial) - 1);
 
                if (serial[0])
                        return PyString_FromString(serial);