[NETFILTER]: Fix stack leakage in iptables

Found running netfilter code under valgrind: we return some
uninitialized stack to userspace (needs root).  Almost certainly
harmless, but this suppressed the valgrind complaint, and
doesn't hurt.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/netfilter/ip_tables.c

@@ -1292,7 +1292,7 @@ do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
 			       sizeof(info.underflow));
 			info.num_entries = t->private->number;
 			info.size = t->private->size;
-			strcpy(info.name, name);
+			memcpy(info.name, name, sizeof(info.name));
 
 			if (copy_to_user(user, &info, *len) != 0)
 				ret = -EFAULT;