From patchwork Sun Apr 19 05:12:15 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 26177 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@bilbo.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 92415B707C for ; Sun, 19 Apr 2009 15:12:49 +1000 (EST) Received: by ozlabs.org (Postfix) id 86DA3DE05F; Sun, 19 Apr 2009 15:12:49 +1000 (EST) Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id 2C4C9DE050 for ; Sun, 19 Apr 2009 15:12:49 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751365AbZDSFMT (ORCPT ); Sun, 19 Apr 2009 01:12:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751015AbZDSFMS (ORCPT ); Sun, 19 Apr 2009 01:12:18 -0400 Received: from wine.ocn.ne.jp ([122.1.235.145]:63844 "EHLO smtp.wine.ocn.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750893AbZDSFMR (ORCPT ); Sun, 19 Apr 2009 01:12:17 -0400 Received: from CLAMP (p1194-ipbf6009marunouchi.tokyo.ocn.ne.jp [114.145.72.194]) by smtp.wine.ocn.ne.jp (Postfix) with ESMTP id E40C032CE; Sun, 19 Apr 2009 14:12:15 +0900 (JST) To: davem@davemloft.net Cc: netdev@vger.kernel.org, linux-security-module@vger.kernel.org Subject: Re: What is lock_sock() before skb_free_datagram() for? From: Tetsuo Handa References: <200904181804.AHC13042.VHFFOOJOFLSQMt@I-love.SAKURA.ne.jp> <20090418.020837.106276006.davem@davemloft.net> <200904182123.HFF13509.MVSJtQHFLFOFOO@I-love.SAKURA.ne.jp> <20090418.212842.163717535.davem@davemloft.net> In-Reply-To: <20090418.212842.163717535.davem@davemloft.net> Message-Id: <200904191412.GIF95380.SVFJOHOFOQtLMF@I-love.SAKURA.ne.jp> X-Mailer: Winbiff [Version 2.51 PL2] X-Accept-Language: ja,en,zh Date: Sun, 19 Apr 2009 14:12:15 +0900 Mime-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org David Miller wrote: > We worked so hard to split out this common code, it is simply > a non-starter for anyone to start putting protocol specific test > into here, or even worse to move this code back to being locally > copied into every protocol implementation. You don't want LSM modules to perform protocol specific test inside __skb_recv_datagram(). I see. > You may want to think about how you can achieve your goals by putting > these unpleasant hooks into some other location. May I insert security_socket_post_recv_datagram() into the caller of skb_recv_datagram() (as shown below)? include/linux/security.h | 39 +++++++++++++++++++++++++++++++++++++++ net/ipv4/raw.c | 5 +++++ net/ipv4/udp.c | 7 +++++++ net/ipv6/raw.c | 5 +++++ net/ipv6/udp.c | 7 +++++++ net/socket.c | 5 +++++ security/capability.c | 13 +++++++++++++ security/security.c | 11 +++++++++++ 8 files changed, 92 insertions(+) --- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- security-testing-2.6.git.orig/net/ipv4/raw.c +++ security-testing-2.6.git/net/ipv4/raw.c @@ -666,6 +666,11 @@ static int raw_recvmsg(struct kiocb *ioc skb = skb_recv_datagram(sk, flags, noblock, &err); if (!skb) goto out; + err = security_socket_post_recv_datagram(sk, skb, flags); + if (err) { + skb_kill_datagram(sk, skb, flags); + goto out; + } copied = skb->len; if (len < copied) { --- security-testing-2.6.git.orig/net/ipv4/udp.c +++ security-testing-2.6.git/net/ipv4/udp.c @@ -901,6 +901,13 @@ try_again: &peeked, &err); if (!skb) goto out; + err = security_socket_post_recv_datagram(sk, skb, flags); + if (err) { + lock_sock(sk); + skb_kill_datagram(sk, skb, flags); + release_sock(sk); + goto out; + } ulen = skb->len - sizeof(struct udphdr); copied = len; --- security-testing-2.6.git.orig/net/ipv6/raw.c +++ security-testing-2.6.git/net/ipv6/raw.c @@ -465,6 +465,11 @@ static int rawv6_recvmsg(struct kiocb *i skb = skb_recv_datagram(sk, flags, noblock, &err); if (!skb) goto out; + err = security_socket_post_recv_datagram(sk, skb, flags); + if (err) { + skb_kill_datagram(sk, skb, flags); + goto out; + } copied = skb->len; if (copied > len) { --- security-testing-2.6.git.orig/net/ipv6/udp.c +++ security-testing-2.6.git/net/ipv6/udp.c @@ -208,6 +208,13 @@ try_again: &peeked, &err); if (!skb) goto out; + err = security_socket_post_recv_datagram(sk, skb, flags); + if (err) { + lock_sock(sk); + skb_kill_datagram(sk, skb, flags); + release_sock(sk); + goto out; + } ulen = skb->len - sizeof(struct udphdr); copied = len;