Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755540AbXJaXtz (ORCPT ); Wed, 31 Oct 2007 19:49:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752530AbXJaXtr (ORCPT ); Wed, 31 Oct 2007 19:49:47 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:54817 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752520AbXJaXtq (ORCPT ); Wed, 31 Oct 2007 19:49:46 -0400 Date: Wed, 31 Oct 2007 18:49:45 -0500 From: "Serge E. Hallyn" To: lkml Cc: linux-security-module@vger.kernel.org, Andrew Morton , Andrew Morgan , Chris Wright , "Theodore Ts'o" , Stephen Smalley , "Rafael J. Wysocki" , Natalie Protasevich Subject: [PATCH] file capabilities: allow sigcont within session (v2) Message-ID: <20071031234945.GA16455@sergelap.austin.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1793 Lines: 49 >From 5bff8967f45a35f858b96ca673d9bf98eac53d49 Mon Sep 17 00:00:00 2001 From: Serge E. Hallyn Date: Wed, 31 Oct 2007 11:22:04 -0500 Subject: [PATCH 1/1] file capabilities: allow sigcont within session (v2) (This is a proposed fix to http://bugzilla.kernel.org/show_bug.cgi?id=9247) Allow sigcont to be sent to a process with greater capabilities if it is in the same session. Otherwise, a shell from which I've started a root shell and done 'suspend' can't be restarted by the parent shell. Also don't do file-capabilities signaling checks when uids for the processes don't match, since the standard check_kill_permission will have done those checks. Signed-off-by: Serge E. Hallyn --- security/commoncap.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/security/commoncap.c b/security/commoncap.c index bf67871..4de6857 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -526,6 +526,15 @@ int cap_task_kill(struct task_struct *p, struct siginfo *info, if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info))) return 0; + /* if tasks have same uid, then check_kill_permission did check */ + if (current->uid == p->uid || current->euid == p->uid || + current->uid == p->suid || current->euid == p->suid) + return 0; + + /* sigcont is permitted within same session */ + if (sig == SIGCONT && (task_session_nr(current)==task_session_nr(p))) + return 0; + if (secid) /* * Signal sent as a particular user. -- 1.5.1.1.GIT - 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/