madwifi plugin: Fix buffer handling around `readlink'.

readlink(2) doesn't null-terminate the buffer in any case. Thanks to Ondrej for
pointing this out.

diff --git a/src/madwifi.c b/src/madwifi.c
index 9d973ec059a94335ca42477a8791d3dd9ef27a8c..f0230f9b2e4cf13b413d92cc1a5b4d634c589b9f 100644 (file)
--- a/src/madwifi.c
+++ b/src/madwifi.c
@@ -769,8 +769,8 @@ process_device (int sk, const char *dev)
 static int
 check_devname (const char *dev)
 {
-       char buf[256];
-       char buf2[256];
+       char buf[PATH_MAX];
+       char buf2[PATH_MAX];
        int i;
 
        if (dev[0] == '.')
@@ -779,10 +779,10 @@ check_devname (const char *dev)
        ssnprintf (buf, sizeof (buf), "/sys/class/net/%s/device/driver", dev);
        buf[sizeof (buf) - 1] = 0;
 
+       memset (buf2, 0, sizeof (buf2));
        i = readlink (buf, buf2, sizeof (buf2) - 1);
        if (i < 0)
                return 0;
-       buf2[sizeof (buf2) - 1] = 0;
 
        if (strstr (buf2, "/drivers/ath_") == NULL)
                return 0;