From: Florian Forster <octo@huhu.verplant.org>
Date: Sun, 16 Aug 2009 07:13:31 +0000 (+0200)
Subject: madwifi plugin: Fix buffer handling around `readlink'.
X-Git-Tag: collectd-4.8.0~49
X-Git-Url: https://git.octo.it/?a=commitdiff_plain;h=317e5932836ec040ccf3a19054a922eb7f00bd0a;p=collectd.git

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 9d973ec0..f0230f9b 100644
--- 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;