Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2558C433FE for ; Wed, 24 Nov 2021 17:02:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349426AbhKXRFp (ORCPT ); Wed, 24 Nov 2021 12:05:45 -0500 Received: from mail-m972.mail.163.com ([123.126.97.2]:47956 "EHLO mail-m972.mail.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349416AbhKXRFm (ORCPT ); Wed, 24 Nov 2021 12:05:42 -0500 X-Greylist: delayed 913 seconds by postgrey-1.27 at vger.kernel.org; Wed, 24 Nov 2021 12:05:39 EST DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=f7cxo 81Jyy/MlDMAZmvQHlwJdJ/bK+AjY9CliasYTAc=; b=Jw0jKPWRfT84gkTZrNC3t W6e9i6tbvxXiLkoiHEQ1QTIqPv4hMZClRVoN0y2GogwVHBwsQy1VijP5Zightnp0 zp74VY/g+mw+0xHTldt4G/lc0wimgrPzYO3bgy7b5u6Y5C8Wbeb7eYrTgxkCiGqf 0gdrObnvmYXR+/6GgVoJ28= Received: from localhost.localdomain (unknown [218.106.182.227]) by smtp2 (Coremail) with SMTP id GtxpCgD3RCmEbJ5htkyJKQ--.4644S4; Thu, 25 Nov 2021 00:47:11 +0800 (CST) From: Jianglei Nie To: daniel.lezcano@kernel.org, rafael@kernel.org Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Jianglei Nie Subject: [PATCH] powercap: DTPM: Fix reference leak in cpuhp_dtpm_cpu_offline() Date: Thu, 25 Nov 2021 00:46:57 +0800 Message-Id: <20211124164657.20519-1-niejianglei2021@163.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: GtxpCgD3RCmEbJ5htkyJKQ--.4644S4 X-Coremail-Antispam: 1Uf129KBjvJXoW7AFyDXr1xWw48JFy5JF43KFg_yoW8Aw4Dpr s8K3yav348tFWDK397J3WDXFyYvF92ya9YkrW3Gw1rZa43X3WFgw4DKryYqF1rCrn5Cw13 try5Xay8Jay5JFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07bOv3bUUUUU= X-Originating-IP: [218.106.182.227] X-CM-SenderInfo: xqlhyxxdqjzvrlsqjii6rwjhhfrp/xtbBORxVjF-PKEzbggABsQ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jianglei Nie In line 153 (#1), cpufreq_cpu_get() increments the kobject reference counter of the policy it returned on success. According to the document, the policy returned by cpufreq_cpu_get() has to be released with the help of cpufreq_cpu_put() to balance its kobject reference counter properly. Forgetting the cpufreq_cpu_put() operation will result in reference leak. We can fix it by calling cpufreq_cpu_put() before the function returns (#2, #3 and #4). 147 static int cpuhp_dtpm_cpu_offline(unsigned int cpu) 148 { 153 policy = cpufreq_cpu_get(cpu); // #1: reference increment 155 if (!policy) 156 return 0; 158 pd = em_cpu_get(cpu); 159 if (!pd) 160 return -EINVAL; // #2: missing reference decrement 166 if (cpumask_weight(policy->cpus) != 1) 167 return 0; // #3: missing reference decrement 174 return 0; // #4: missing reference decrement 175 } Signed-off-by: Jianglei Nie --- drivers/powercap/dtpm_cpu.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/powercap/dtpm_cpu.c b/drivers/powercap/dtpm_cpu.c index 51c366938acd..182a07ee14b6 100644 --- a/drivers/powercap/dtpm_cpu.c +++ b/drivers/powercap/dtpm_cpu.c @@ -156,21 +156,26 @@ static int cpuhp_dtpm_cpu_offline(unsigned int cpu) return 0; pd = em_cpu_get(cpu); - if (!pd) + if (!pd) { + cpufreq_cpu_put(policy); return -EINVAL; + } dtpm = per_cpu(dtpm_per_cpu, cpu); power_sub(dtpm, pd); - if (cpumask_weight(policy->cpus) != 1) + if (cpumask_weight(policy->cpus) != 1) { + cpufreq_cpu_put(policy); return 0; + } for_each_cpu(cpu, policy->related_cpus) per_cpu(dtpm_per_cpu, cpu) = NULL; dtpm_unregister(dtpm); + cpufreq_cpu_put(policy); return 0; } -- 2.25.1