From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757569AbZKROwB (ORCPT ); Wed, 18 Nov 2009 09:52:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757549AbZKROv7 (ORCPT ); Wed, 18 Nov 2009 09:51:59 -0500 Received: from server1.wserver.cz ([82.113.45.157]:51175 "EHLO server1.wserver.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753962AbZKROv6 (ORCPT ); Wed, 18 Nov 2009 09:51:58 -0500 From: Jiri Slaby To: jirislaby@gmail.com Cc: mingo@elte.hu, nhorman@tuxdriver.com, sfr@canb.auug.org.au, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, marcin.slusarz@gmail.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, torvalds@linux-foundation.org, Jiri Slaby , James Morris , Heiko Carstens Subject: [PATCH 02/16] core: do security check under task_lock Date: Wed, 18 Nov 2009 15:51:48 +0100 Message-Id: <1258555922-2064-2-git-send-email-jslaby@novell.com> X-Mailer: git-send-email 1.6.4.2 In-Reply-To: <4B040A03.2020508@gmail.com> References: <4B040A03.2020508@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Do security_task_setrlimit under task_lock. Other tasks may change limits under our hands while we are checking limits inside the function. From now on, they can't. Signed-off-by: Jiri Slaby Cc: James Morris Cc: Heiko Carstens Cc: Andrew Morton Cc: Ingo Molnar --- kernel/sys.c | 16 +++++++--------- 1 files changed, 7 insertions(+), 9 deletions(-) diff --git a/kernel/sys.c b/kernel/sys.c index 605ab9c..0f86199 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1243,7 +1243,7 @@ int setrlimit(struct task_struct *tsk, unsigned int resource, struct rlimit *new_rlim) { struct rlimit *old_rlim; - int retval; + int retval = 0; if (new_rlim->rlim_cur > new_rlim->rlim_max) return -EINVAL; @@ -1260,10 +1260,6 @@ int setrlimit(struct task_struct *tsk, unsigned int resource, } } - retval = security_task_setrlimit(tsk, resource, new_rlim); - if (retval) - goto out; - if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { /* * The caller is asking for an immediate RLIMIT_CPU @@ -1276,11 +1272,13 @@ int setrlimit(struct task_struct *tsk, unsigned int resource, old_rlim = tsk->signal->rlim + resource; task_lock(tsk->group_leader); - if ((new_rlim->rlim_max <= old_rlim->rlim_max) || - capable(CAP_SYS_RESOURCE)) - *old_rlim = *new_rlim; - else + if ((new_rlim->rlim_max > old_rlim->rlim_max) && + !capable(CAP_SYS_RESOURCE)) retval = -EPERM; + if (!retval) + retval = security_task_setrlimit(tsk, resource, new_rlim); + if (!retval) + *old_rlim = *new_rlim; task_unlock(tsk->group_leader); if (retval || resource != RLIMIT_CPU) -- 1.6.4.2