From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161506AbcBQM2H (ORCPT ); Wed, 17 Feb 2016 07:28:07 -0500 Received: from terminus.zytor.com ([198.137.202.10]:56704 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422884AbcBQM1K (ORCPT ); Wed, 17 Feb 2016 07:27:10 -0500 Date: Wed, 17 Feb 2016 04:24:55 -0800 From: tip-bot for Thomas Gleixner Message-ID: Cc: acme@redhat.com, linux-kernel@vger.kernel.org, jolsa@redhat.com, tglx@linutronix.de, torvalds@linux-foundation.org, peterz@infradead.org, vincent.weaver@maine.edu, hpa@zytor.com, mingo@kernel.org, eranian@google.com Reply-To: tglx@linutronix.de, torvalds@linux-foundation.org, eranian@google.com, mingo@kernel.org, hpa@zytor.com, vincent.weaver@maine.edu, peterz@infradead.org, linux-kernel@vger.kernel.org, acme@redhat.com, jolsa@redhat.com In-Reply-To: <20160209201007.843269966@linutronix.de> References: <20160209201007.843269966@linutronix.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf/core: Plug potential memory leak in CPU_UP_PREPARE Git-Commit-ID: 059fcd8cd16622da6513804a7a3e826d152c6c96 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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 059fcd8cd16622da6513804a7a3e826d152c6c96 Gitweb: http://git.kernel.org/tip/059fcd8cd16622da6513804a7a3e826d152c6c96 Author: Thomas Gleixner AuthorDate: Tue, 9 Feb 2016 20:11:34 +0000 Committer: Ingo Molnar CommitDate: Wed, 17 Feb 2016 10:37:30 +0100 perf/core: Plug potential memory leak in CPU_UP_PREPARE If CPU_UP_PREPARE is called it is not guaranteed, that a previously allocated and assigned hash has been freed already, but perf_event_init_cpu() unconditionally allocates and assignes a new hash if the swhash is referenced. By overwriting the pointer the existing hash is not longer accessible. Verify that there is no hash assigned on this cpu before allocating and assigning a new one. Signed-off-by: Thomas Gleixner Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Vince Weaver Link: http://lkml.kernel.org/r/20160209201007.843269966@linutronix.de Signed-off-by: Ingo Molnar --- kernel/events/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 4aa64a8..0d58522 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9206,7 +9206,7 @@ static void perf_event_init_cpu(int cpu) struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); mutex_lock(&swhash->hlist_mutex); - if (swhash->hlist_refcount > 0) { + if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) { struct swevent_hlist *hlist; hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));