Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753706AbaGVHot (ORCPT ); Tue, 22 Jul 2014 03:44:49 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:39511 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750743AbaGVHoq (ORCPT ); Tue, 22 Jul 2014 03:44:46 -0400 Date: Tue, 22 Jul 2014 10:42:14 +0300 From: Dan Carpenter To: Julian Anastasov Cc: Andrey Utkin , "linux-kernel@vger.kernel.org" , kernel-janitors@vger.kernel.org, coreteam@netfilter.org, netfilter-devel@vger.kernel.org, lvs-devel@vger.kernel.org, netdev@vger.kernel.org, dcb314@hotmail.com, David Miller , kadlec@blackhole.kfki.hu, Patrick McHardy , pablo@netfilter.org, Simon Horman , wensong@linux-vs.org Subject: Re: [PATCH 3/5] net/netfilter/ipvs/ip_vs_ctl.c: drop argument range check just before the check for equality Message-ID: <20140722074214.GL25880@mwanda> References: <1405697638-23767-1-git-send-email-andrey.krieger.utkin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 21, 2014 at 11:01:56PM +0300, Julian Anastasov wrote: > @@ -2333,13 +2339,12 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) > struct ip_vs_dest_user_kern udest; > struct netns_ipvs *ipvs = net_ipvs(net); > > + BUILD_BUG_ON(sizeof(arg) > 256); 256 is off-by-one because u8 ranges from 0-255 so we are never able to copy 256 bytes into the "arg" buffer. > - if (copylen > 128) > + if (*len < (int) copylen || *len < 0) { > + pr_err("get_ctl: len %d < %u\n", *len, copylen); Don't let users flood dmesg. Just return an error. (This can be triggered by non-root as well). > return -EINVAL; > + } regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/