From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9A5BC433E9 for ; Mon, 28 Dec 2020 10:29:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C33F2207C9 for ; Mon, 28 Dec 2020 10:29:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727224AbgL1K3X (ORCPT ); Mon, 28 Dec 2020 05:29:23 -0500 Received: from foss.arm.com ([217.140.110.172]:50688 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727018AbgL1K3X (ORCPT ); Mon, 28 Dec 2020 05:29:23 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 72D431FB; Mon, 28 Dec 2020 02:28:37 -0800 (PST) Received: from [10.57.30.50] (unknown [10.57.30.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0EDF13F6CF; Mon, 28 Dec 2020 02:28:33 -0800 (PST) Subject: Re: [PATCH] thermal: cpufreq_cooling: fix slab OOB issue To: Michael Kao , fan.chen@mediatek.com, Zhang Rui , Daniel Lezcano , linux-pm@vger.kernel.org, srv_heupstream@mediatek.com Cc: Eduardo Valentin , Rob Herring , Mark Rutland , Matthias Brugger , hsinyi@chromium.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, brian-sy yang References: <20201223074849.1989-1-michael.kao@mediatek.com> From: Lukasz Luba Message-ID: <010350df-e094-cf12-1c17-f56aa4b20b9f@arm.com> Date: Mon, 28 Dec 2020 10:28:31 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20201223074849.1989-1-michael.kao@mediatek.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/23/20 7:48 AM, Michael Kao wrote: > From: brian-sy yang > > Slab OOB issue is scanned by KASAN in cpu_power_to_freq(). > If power is limited below the power of OPP0 in EM table, > it will cause slab out-of-bound issue with negative array > index. > > Return the lowest frequency if limited power cannot found > a suitable OPP in EM table to fix this issue. > > Backtrace: > [] die+0x104/0x5ac > [] bug_handler+0x64/0xd0 > [] brk_handler+0x160/0x258 > [] do_debug_exception+0x248/0x3f0 > [] el1_dbg+0x14/0xbc > [] __kasan_report+0x1dc/0x1e0 > [] kasan_report+0x10/0x20 > [] __asan_report_load8_noabort+0x18/0x28 > [] cpufreq_power2state+0x180/0x43c > [] power_actor_set_power+0x114/0x1d4 > [] allocate_power+0xaec/0xde0 > [] power_allocator_throttle+0x3ec/0x5a4 > [] handle_thermal_trip+0x160/0x294 > [] thermal_zone_device_check+0xe4/0x154 > [] process_one_work+0x5e4/0xe28 > [] worker_thread+0xa4c/0xfac > [] kthread+0x33c/0x358 > [] ret_from_fork+0xc/0x18 Thank you for looking at this and sending a fix. It's worth to add the 'fixes' line: Fixes: 371a3bc79c11b ("thermal/drivers/cpufreq_cooling: Fix wrong frequency converted from power") IIRC that patch was sent to stable trees. Might be worth to check and apply this fix. > > Signed-off-by: brian-sy yang Reviewed-by: Lukasz Luba > --- > drivers/thermal/cpufreq_cooling.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c > index cc2959f22f01..fb33b3480a8f 100644 > --- a/drivers/thermal/cpufreq_cooling.c > +++ b/drivers/thermal/cpufreq_cooling.c > @@ -123,7 +123,7 @@ static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev, > { > int i; > > - for (i = cpufreq_cdev->max_level; i >= 0; i--) { > + for (i = cpufreq_cdev->max_level; i > 0; i--) { > if (power >= cpufreq_cdev->em->table[i].power) > break; > } >