Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964971AbWCTVhK (ORCPT ); Mon, 20 Mar 2006 16:37:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964975AbWCTVhK (ORCPT ); Mon, 20 Mar 2006 16:37:10 -0500 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:47233 "EHLO sorel.sous-sol.org") by vger.kernel.org with ESMTP id S964971AbWCTVhH (ORCPT ); Mon, 20 Mar 2006 16:37:07 -0500 Date: Mon, 20 Mar 2006 13:36:36 -0800 From: Chris Wright To: Catherine Zhang Cc: Ingo Oeser , Chris Wright , Ingo Oeser , davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Andrew Morton Subject: Re: [PATCH] scm: fold __scm_send() into scm_send() Message-ID: <20060320213636.GT15997@sorel.sous-sol.org> References: <200603130139.k2D1dpSQ021279@shell0.pdx.osdl.net> <200603132105.32794.ioe-lkml@rameria.de> <20060313173103.7681b49d.akpm@osdl.org> <200603201244.58507.netdev@axxeo.de> <20060320201802.GS15997@sorel.sous-sol.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060320201802.GS15997@sorel.sous-sol.org> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2328 Lines: 68 * Chris Wright (chrisw@sous-sol.org) wrote: > * Ingo Oeser (netdev@axxeo.de) wrote: > > Hi Chris, > > > > Andrew Morton wrote: > > > Ingo Oeser wrote: > > > > > > > > -int scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) > > > > -{ > > > > - struct task_struct *p = current; > > > > - scm->creds = (struct ucred) { > > > > - .uid = p->uid, > > > > - .gid = p->gid, > > > > - .pid = p->tgid > > > > - }; > > > > - scm->fp = NULL; > > > > - scm->sid = security_sk_sid(sock->sk, NULL, 0); > > > > - scm->seq = 0; > > > > - if (msg->msg_controllen <= 0) > > > > - return 0; > > > > - return __scm_send(sock, msg, scm); > > > > -} > > > > > > It's worth noting that scm_send() will call security_sk_sid() even if > > > (msg->msg_controllen <= 0). > > > > Chris, do you know if this is needed in this case? > > This whole thing is looking broken. I'm still trying to find the original > patch which caused the series of broken patches on top. OK, it starts here from Catherine's patch: include/net/scm.h::scm_recv() + if (test_bit(SOCK_PASSSEC, &sock->flags)) { + err = security_sid_to_context(scm->sid, &scontext, &scontext_len); + if (!err) + put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, scontext_len, scontext); + } Catherine, the security_sid_to_context() is a raw SELinux function which crept into core code and should not have been there. The fallout fixes included conditionally exporting security_sid_to_context, and finally scm_send/recv unlining. The end result in -mm looks broken to me. Specifically, it now does: ucred->uid = tsk->uid; ucred->gid = tsk->gid; ucred->pid = tsk->tgid; scm->fp = NULL; scm->seq = 0; if (msg->msg_controllen <= 0) return 0; scm->sid = security_sk_sid(sock->sk, NULL, 0); The point of Catherine's original patch was to make sure there's always a security identifier associated with AF_UNIX messages. So receiver can always check it (same as having credentials even w/out sender control message passing them). Now we will have garbage for sid. thanks, -chris - 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/