From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966783AbcIVTWf (ORCPT ); Thu, 22 Sep 2016 15:22:35 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56370 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965792AbcIVRfZ (ORCPT ); Thu, 22 Sep 2016 13:35:25 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Rutland , Pawel Moll Subject: [PATCH 4.4 059/118] bus: arm-ccn: Do not attempt to configure XPs for cycle counter Date: Thu, 22 Sep 2016 19:29:19 +0200 Message-Id: <20160922172941.715281318@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20160922172938.643879685@linuxfoundation.org> References: <20160922172938.643879685@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pawel Moll commit b7c1beb278e8e3dc664ed3df3fc786db126120a9 upstream. Fuzzing the CCN perf driver revealed a small but definitely dangerous mistake in the event setup code. When a cycle counter is requested, the driver should not reconfigure the events bus at all, otherwise it will corrupt (in most but the simplest cases) its configuration and may end up accessing XP array out of its bounds and corrupting control registers. Reported-by: Mark Rutland Reviewed-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Pawel Moll Signed-off-by: Greg Kroah-Hartman --- drivers/bus/arm-ccn.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -895,6 +895,10 @@ static void arm_ccn_pmu_xp_dt_config(str struct arm_ccn_component *xp; u32 val, dt_cfg; + /* Nothing to do for cycle counter */ + if (hw->idx == CCN_IDX_PMU_CYCLE_COUNTER) + return; + if (CCN_CONFIG_TYPE(event->attr.config) == CCN_TYPE_XP) xp = &ccn->xp[CCN_CONFIG_XP(event->attr.config)]; else