udev buffer overrun fix (2nd try)

@@ -146,7 +146,7 @@
 	int tail;
 
 	strncpy(filename, udev_root, sizeof(filename));
-	strncat(filename, dev->name, sizeof(filename));
+	strncat(filename, dev->name, sizeof(filename) - strlen(udev_root) - 1);
 
 	switch (dev->type) {
 	case 'b':

@@ -226,7 +226,7 @@
 				break;
 
 			strncpy(filename, udev_root, sizeof(filename));
-			strncat(filename, linkname, sizeof(filename));
+			strncat(filename, linkname, sizeof(filename) - strlen(udev_root) - 1);
 			dbg("symlink '%s' to node '%s' requested", filename, dev->name);
 			if (!fake)
 				if (strrchr(linkname, '/'))

@@ -243,13 +243,15 @@
 			}
 			while (linkname[i] != '\0') {
 				if (linkname[i] = '/')
-					strcat(linktarget, "../");
+					strncat(linktarget, "../",
+						sizeof(linktarget) - strlen(linktarget) - 1);
 				i++;
 			}
 
 			if (linktarget[0] = '\0')
 				strcpy(linktarget, "./");
-			strcat(linktarget, &dev->name[tail]);
+			strncat(linktarget, &dev->name[tail],
+				sizeof(linktarget) - strlen(linktarget) - 1);
 
 			/* unlink existing files to ensure that our symlink is created */
 			if (!fake && (lstat(filename, &stats) = 0)) {