From: Kerin Millar <kerframil@gmail.com>

The ifconfig tool does not bother checking the return value of
lookup_interface() in one instance. This results in a null pointer
dereference for those cases where the lookup fails. Fixes a segfault
reported by Alex Efros in a comment on bug 238363. The fix is already
present in CVS upstream.

--- net-tools-1.60_p20071202044231-r1.orig/ifconfig.c	2007-12-02 04:42:31.000000000 +0000
+++ net-tools-1.60_p20071202044231-r1/ifconfig.c	2009-07-23 03:58:52.609949053 +0100
@@ -112,6 +112,9 @@ static int if_print(char *ifname)
 	struct interface *ife;
 
 	ife = lookup_interface(ifname);
+        if (!ife) {
+                return -1;
+        }
 	res = do_if_fetch(ife); 
 	if (res >= 0) 
 	    ife_print(ife);