From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Paris Subject: Re: [PATCH] Audit: fix audit nlmsg_len from the kernel Date: Tue, 02 Jun 2009 16:51:35 -0400 Message-ID: <1243975895.2923.9.camel@dhcp231-142.rdu.redhat.com> References: <20090528231753.14980.15527.stgit@paris.rdu.redhat.com> <1243975082.2923.6.camel@dhcp231-142.rdu.redhat.com> <200906021645.02794.sgrubb@redhat.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200906021645.02794.sgrubb@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-audit-bounces@redhat.com Errors-To: linux-audit-bounces@redhat.com To: Steve Grubb Cc: linux-audit@redhat.com, viro@zeniv.linux.org.uk List-Id: linux-audit@redhat.com On Tue, 2009-06-02 at 16:45 -0400, Steve Grubb wrote: > On Tuesday 02 June 2009 04:38:02 pm Eric Paris wrote: > > > But lets fix it anyway rather than rely on dumb luck and implementation > > > details. > > > > Self NAK. Userspace was also written by someone who didn't know > > netlink. Since userspace is half using the netlink macros and half > > depending on this broken nlmsg_len implementation I don't think we can > > make any changes in the kernel and they wouldn't be backwards > > compatible... > > The netlink code is the oldest part of the audit code and predates my > involvement. We could fix this if userspace had a way of querying the kernel to > see what the audit capabilities are. There have been many times that I've > wanted a way to ask the kernel if certain things are supported. > > -Steve Although yes, that lets new userspace work on old and new kernels it's not the problem I'm thinking about. I'm more worried about new kernel breaking old userspace, a huge no no, since the new kernel has no way of knowing if userspace supports correct netlink semantics or not.... In any case, this patch should certainly not be applied. -Eric