From: Thomas Graf <tgraf@infradead.org>
To: Ben Hutchings <bhutchings@solarflare.com>
Cc: Greg Rose <gregory.v.rose@intel.com>,
netdev@vger.kernel.org, davem@davemloft.net
Subject: Re: [RFC V2 PATCH] rtnetlink: Fix problem with buffer allocation
Date: Wed, 15 Feb 2012 09:08:14 -0500 [thread overview]
Message-ID: <20120215140814.GA29673@canuck.infradead.org> (raw)
In-Reply-To: <1329253993.2443.30.camel@bwh-desktop>
On Tue, Feb 14, 2012 at 09:13:13PM +0000, Ben Hutchings wrote:
> > + struct rtattr *ext_req;
> > + u32 *ext_req_data;
> > + req = (struct rtnl_req_extended *)cb->nlh;
> > + ext_req = (struct rtattr *)&req->ext;
> > + if (ext_req->rta_type == IFLA_EXT_MASK) {
> > + ext_req_data = RTA_DATA(ext_req);
> > + ext_filter_mask = *ext_req_data;
> > + }
> > + }
>
> We cannot trust a flag to tell us what the length of the message is. We
> have to check the value of nlmsg_len (which netlink has already
> validated as being within the skb length and >= our declared request
> header length). I think that makes the flag redundant.
>
> In fact, I think we should really use nlmsg_parse() here. That might be
> overkill when there's only a single valid attribute; I don't know.
I think it's worth the effort. You get all the validation for free. And
please use the netlink interface in <net/netlink.h>, the rtattr based
interface has been deprecated a while ago.
next prev parent reply other threads:[~2012-02-15 14:08 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-12 19:13 [RFC V2 PATCH] rtnetlink: Fix problem with buffer allocation Greg Rose
2012-02-13 17:28 ` Stephen Hemminger
2012-02-13 18:24 ` Rose, Gregory V
2012-02-14 21:13 ` Ben Hutchings
2012-02-14 21:27 ` Rose, Gregory V
2012-02-14 21:31 ` David Miller
2012-02-14 21:41 ` Rose, Gregory V
2012-02-14 21:48 ` David Miller
2012-02-14 21:51 ` Rose, Gregory V
2012-02-15 14:08 ` Thomas Graf [this message]
2012-02-15 16:32 ` Rose, Gregory V
2012-02-14 21:22 ` David Miller
2012-02-14 21:34 ` Rose, Gregory V
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