From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753638Ab3KSTQV (ORCPT ); Tue, 19 Nov 2013 14:16:21 -0500 Received: from terminus.zytor.com ([198.137.202.10]:51686 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753604Ab3KSTQQ (ORCPT ); Tue, 19 Nov 2013 14:16:16 -0500 Date: Tue, 19 Nov 2013 11:15:33 -0800 From: tip-bot for Peter Zijlstra Message-ID: Cc: linux-kernel@vger.kernel.org, anton@samba.org, hpa@zytor.com, mingo@kernel.org, preeti@linux.vnet.ibm.com, peterz@infradead.org, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, anton@samba.org, linux-kernel@vger.kernel.org, preeti@linux.vnet.ibm.com, peterz@infradead.org, tglx@linutronix.de In-Reply-To: <20131118113701.GF3866@twins.programming.kicks-ass.net> References: <20131118113701.GF3866@twins.programming.kicks-ass.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/urgent] sched: Avoid NULL dereference on sd_busy Git-Commit-ID: 42eb088ed246a5a817bb45a8b32fe234cf1c0f8b X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.1 (terminus.zytor.com [127.0.0.1]); Tue, 19 Nov 2013 11:15:39 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 42eb088ed246a5a817bb45a8b32fe234cf1c0f8b Gitweb: http://git.kernel.org/tip/42eb088ed246a5a817bb45a8b32fe234cf1c0f8b Author: Peter Zijlstra AuthorDate: Tue, 19 Nov 2013 16:41:49 +0100 Committer: Ingo Molnar CommitDate: Tue, 19 Nov 2013 17:01:16 +0100 sched: Avoid NULL dereference on sd_busy Commit 37dc6b50cee9 ("sched: Remove unnecessary iteration over sched domains to update nr_busy_cpus") forgot to clear 'sd_busy' under some conditions leading to a possible NULL deref in set_cpu_sd_state_idle(). Reported-by: Anton Blanchard Cc: Preeti U Murthy Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20131118113701.GF3866@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c180860..a1591ca 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4910,8 +4910,9 @@ static void update_top_cache_domain(int cpu) if (sd) { id = cpumask_first(sched_domain_span(sd)); size = cpumask_weight(sched_domain_span(sd)); - rcu_assign_pointer(per_cpu(sd_busy, cpu), sd->parent); + sd = sd->parent; /* sd_busy */ } + rcu_assign_pointer(per_cpu(sd_busy, cpu), sd); rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); per_cpu(sd_llc_size, cpu) = size;