From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757675Ab0DVTy1 (ORCPT ); Thu, 22 Apr 2010 15:54:27 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:52029 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757654Ab0DVTyQ (ORCPT ); Thu, 22 Apr 2010 15:54:16 -0400 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, "Paul E. McKenney" Subject: [PATCH tip/core/urgent 3/3] sched: protect __sched_setscheduler() access to cgroups Date: Thu, 22 Apr 2010 12:54:07 -0700 Message-Id: <1271966047-9701-3-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.0 In-Reply-To: <20100422195345.GA9639@linux.vnet.ibm.com> References: <20100422195345.GA9639@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A given task's cgroups structures must remain while that task is running due to reference counting, so this is presumably a false positive. Updated to reflect feedback from Tetsuo Handa. Signed-off-by: Paul E. McKenney --- kernel/sched.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 14c44ec..f425a2b 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4575,9 +4575,13 @@ recheck: * Do not allow realtime tasks into groups that have no runtime * assigned. */ + rcu_read_lock(); if (rt_bandwidth_enabled() && rt_policy(policy) && - task_group(p)->rt_bandwidth.rt_runtime == 0) + task_group(p)->rt_bandwidth.rt_runtime == 0) { + rcu_read_unlock(); return -EPERM; + } + rcu_read_unlock(); #endif retval = security_task_setscheduler(p, policy, param); -- 1.7.0