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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 609DFC33C9B for ; Mon, 6 Jan 2020 09:44:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3467221734 for ; Mon, 6 Jan 2020 09:44:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="h3uH4bw2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726050AbgAFJo0 (ORCPT ); Mon, 6 Jan 2020 04:44:26 -0500 Received: from mail-pf1-f194.google.com ([209.85.210.194]:44716 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725821AbgAFJo0 (ORCPT ); Mon, 6 Jan 2020 04:44:26 -0500 Received: by mail-pf1-f194.google.com with SMTP id 195so25872308pfw.11; Mon, 06 Jan 2020 01:44:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=KtGrKb7t1nXkvA9RAp03OXaiGM0Udf6t6g9rmOrwqQA=; b=h3uH4bw2GU+o7uTeRb6skr6Lw6iWOzi9RYNZW+55FiG0+SlNjQei6NHPEjTEDs+5nI HxYgS7bX6DgDzLlZRkirtbIM6O4tvP+ZtsdYxpaHg34HubMIlgcROK9AjKM+YESs6juR 4FA4EJiZq2VK5wshg1aBt5whcBt33ETeDV9DxiBzYCd9vyiMm7dWgfpK++DrsLul5NCz +gSjZOjPIr0sgF+BpSEIE/Hei4C82qIjjGUfC+ATL4FqVOV5fbfk8NXlcqehG2W85uUe uqBbmBXCt9uqRNSWkCTDWHtpZ2NovetviHdgDzrlhKnoc6MJl4mCF0vnyXMdyV9yS5U/ Ya8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=KtGrKb7t1nXkvA9RAp03OXaiGM0Udf6t6g9rmOrwqQA=; b=c6cvt6kXh15w2RlLb/bYt0dqwLzdOMuwRiASEKFf6dWzLiWxbkGuZjo9+zfq7G6cUH sJNGgyJaDTDsSxhSs2fYwxmL7ox6Z7I+JB6II8OBdWPc9lqHRuTOHaPT2jztlTv5FjJ1 1YZrxzNDLCZw7+AR9ZHKWeee1F+JEPfzt71y4H/M6MDGj886p3o72PJtTPiO7Q4ahdpj iy4vBH8gk0Bal+N3lY7YvXdjqHlyptfX2MaJ6GGwwjLJeux8kddHnAmVopwcLv/MhCqk rn40r6NFBqM6ImM1hE7vwlm4ZZZBo433P6aa+eo82RywEveE+rB/+DxGQPFRyNcho6cS iPNQ== X-Gm-Message-State: APjAAAUzeAlePa0IKTRre6Jq9iTOkr7RR0qMpmx8+ir1hx+EMjZn8xEj yYFonlY6pAZaZRztC2GGOck= X-Google-Smtp-Source: APXvYqwXV771FUqOJJoDqNegv2vvgsnsYNEq3vey/xKO088jvc38DW99nYZ6CpWk+IyeSVRKLC6AAQ== X-Received: by 2002:a63:6c82:: with SMTP id h124mr109322399pgc.328.1578303865779; Mon, 06 Jan 2020 01:44:25 -0800 (PST) Received: from localhost ([43.224.245.179]) by smtp.gmail.com with ESMTPSA id u26sm74215521pfn.46.2020.01.06.01.44.24 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Mon, 06 Jan 2020 01:44:25 -0800 (PST) From: qiwuchen55@gmail.com To: kgene@kernel.org, krzk@kernel.org, rjw@rjwysocki.net, viresh.kumar@linaro.org Cc: linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-pm@vger.kernel.org, chenqiwu Subject: [PATCH v2] cpufreq: s3c: avoid use after free issue in xxx_cpufreq_reboot_notifier_evt() Date: Mon, 6 Jan 2020 17:44:21 +0800 Message-Id: <1578303861-7217-1-git-send-email-qiwuchen55@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: chenqiwu There is a potential UAF issue in xxx_cpufreq_reboot_notifier_evt() that the cpufreq policy of cpu0 has been released before using it. So we should make a judgement to avoid it. Signed-off-by: chenqiwu --- changes in v2: - use the combination of cpufreq_cpu_get() and cpufreq_cpu_put() instead of cpufreq_get_policy() in s3c2416-cpufreq.c --- drivers/cpufreq/s3c2416-cpufreq.c | 12 +++++++++++- drivers/cpufreq/s5pv210-cpufreq.c | 11 ++++++++++- 2 files changed, 21 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/s3c2416-cpufreq.c b/drivers/cpufreq/s3c2416-cpufreq.c index 1069103..f07c5d1 100644 --- a/drivers/cpufreq/s3c2416-cpufreq.c +++ b/drivers/cpufreq/s3c2416-cpufreq.c @@ -304,6 +304,7 @@ static int s3c2416_cpufreq_reboot_notifier_evt(struct notifier_block *this, { struct s3c2416_data *s3c_freq = &s3c2416_cpufreq; int ret; + struct cpufreq_policy *policy; mutex_lock(&cpufreq_lock); @@ -318,7 +319,16 @@ static int s3c2416_cpufreq_reboot_notifier_evt(struct notifier_block *this, */ if (s3c_freq->is_dvs) { pr_debug("cpufreq: leave dvs on reboot\n"); - ret = cpufreq_driver_target(cpufreq_cpu_get(0), FREQ_SLEEP, 0); + + policy = cpufreq_cpu_get(0); + if (!policy) { + pr_debug("cpufreq: get no policy for cpu0\n"); + return NOTIFY_BAD; + } + + ret = cpufreq_driver_target(&policy, FREQ_SLEEP, 0); + cpufreq_cpu_put(policy); + if (ret < 0) return NOTIFY_BAD; } diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c index 5d10030..e84281e 100644 --- a/drivers/cpufreq/s5pv210-cpufreq.c +++ b/drivers/cpufreq/s5pv210-cpufreq.c @@ -555,8 +555,17 @@ static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this, unsigned long event, void *ptr) { int ret; + struct cpufreq_policy *policy; + + policy = cpufreq_cpu_get(0); + if (!policy) { + pr_debug("cpufreq: get no policy for cpu0\n"); + return NOTIFY_BAD; + } + + ret = cpufreq_driver_target(policy, SLEEP_FREQ, 0); + cpufreq_cpu_put(policy); - ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ, 0); if (ret < 0) return NOTIFY_BAD; -- 1.9.1