From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 35283168C9 for ; Mon, 8 May 2023 11:04:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD253C4339C; Mon, 8 May 2023 11:04:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683543891; bh=MkBSir096ixF+SGKwT4r3tz493K1/jDeIupkG2T4ODk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1j3rPKmBm1uHgEmto6o02dEyITuH2/4J6NyafQ4ijL64XUq58ZyOQtu0ZFuVkEnM2 xph1gkrf7ZaMU9xXVSyHkXQ7KncXzKujpCBxgWkpA7VrI7eGzvwVG/NPp/eR2rdHX4 vzDX+e+KPw32qeCCy48ZOq/4EbKA5Jiw9Ud4J3oY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jia-Wei Chang , AngeloGioacchino Del Regno , Dan Carpenter , Viresh Kumar , Sasha Levin Subject: [PATCH 6.3 234/694] cpufreq: mediatek: fix KP caused by handler usage after regulator_put/clk_put Date: Mon, 8 May 2023 11:41:09 +0200 Message-Id: <20230508094439.948201657@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094432.603705160@linuxfoundation.org> References: <20230508094432.603705160@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Jia-Wei Chang [ Upstream commit d51e106240bc755cbe59634b70d567c192b045b2 ] Any kind of failure in mtk_cpu_dvfs_info_init() will lead to calling regulator_put() or clk_put() and the KP will occur since the regulator/clk handlers are used after released in mtk_cpu_dvfs_info_release(). To prevent the usage after regulator_put()/clk_put(), the regulator/clk handlers are addressed in a way of "Free the Last Thing Style". Signed-off-by: Jia-Wei Chang Fixes: 4b9ceb757bbb ("cpufreq: mediatek: Enable clocks and regulators") Suggested-by: AngeloGioacchino Del Regno Suggested-by: Dan Carpenter Signed-off-by: Viresh Kumar Signed-off-by: Sasha Levin --- drivers/cpufreq/mediatek-cpufreq.c | 62 +++++++++++++++--------------- 1 file changed, 30 insertions(+), 32 deletions(-) diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c index 01d949707c373..6dc225546a8d6 100644 --- a/drivers/cpufreq/mediatek-cpufreq.c +++ b/drivers/cpufreq/mediatek-cpufreq.c @@ -420,7 +420,7 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu) ret = PTR_ERR(info->inter_clk); dev_err_probe(cpu_dev, ret, "cpu%d: failed to get intermediate clk\n", cpu); - goto out_free_resources; + goto out_free_mux_clock; } info->proc_reg = regulator_get_optional(cpu_dev, "proc"); @@ -428,13 +428,13 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu) ret = PTR_ERR(info->proc_reg); dev_err_probe(cpu_dev, ret, "cpu%d: failed to get proc regulator\n", cpu); - goto out_free_resources; + goto out_free_inter_clock; } ret = regulator_enable(info->proc_reg); if (ret) { dev_warn(cpu_dev, "cpu%d: failed to enable vproc\n", cpu); - goto out_free_resources; + goto out_free_proc_reg; } /* Both presence and absence of sram regulator are valid cases. */ @@ -442,14 +442,14 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu) if (IS_ERR(info->sram_reg)) { ret = PTR_ERR(info->sram_reg); if (ret == -EPROBE_DEFER) - goto out_free_resources; + goto out_disable_proc_reg; info->sram_reg = NULL; } else { ret = regulator_enable(info->sram_reg); if (ret) { dev_warn(cpu_dev, "cpu%d: failed to enable vsram\n", cpu); - goto out_free_resources; + goto out_free_sram_reg; } } @@ -458,13 +458,13 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu) if (ret) { dev_err(cpu_dev, "cpu%d: failed to get OPP-sharing information\n", cpu); - goto out_free_resources; + goto out_disable_sram_reg; } ret = dev_pm_opp_of_cpumask_add_table(&info->cpus); if (ret) { dev_warn(cpu_dev, "cpu%d: no OPP table\n", cpu); - goto out_free_resources; + goto out_disable_sram_reg; } ret = clk_prepare_enable(info->cpu_clk); @@ -533,43 +533,41 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu) out_free_opp_table: dev_pm_opp_of_cpumask_remove_table(&info->cpus); -out_free_resources: - if (regulator_is_enabled(info->proc_reg)) - regulator_disable(info->proc_reg); - if (info->sram_reg && regulator_is_enabled(info->sram_reg)) +out_disable_sram_reg: + if (info->sram_reg) regulator_disable(info->sram_reg); - if (!IS_ERR(info->proc_reg)) - regulator_put(info->proc_reg); - if (!IS_ERR(info->sram_reg)) +out_free_sram_reg: + if (info->sram_reg) regulator_put(info->sram_reg); - if (!IS_ERR(info->cpu_clk)) - clk_put(info->cpu_clk); - if (!IS_ERR(info->inter_clk)) - clk_put(info->inter_clk); + +out_disable_proc_reg: + regulator_disable(info->proc_reg); + +out_free_proc_reg: + regulator_put(info->proc_reg); + +out_free_inter_clock: + clk_put(info->inter_clk); + +out_free_mux_clock: + clk_put(info->cpu_clk); return ret; } static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info) { - if (!IS_ERR(info->proc_reg)) { - regulator_disable(info->proc_reg); - regulator_put(info->proc_reg); - } - if (!IS_ERR(info->sram_reg)) { + regulator_disable(info->proc_reg); + regulator_put(info->proc_reg); + if (info->sram_reg) { regulator_disable(info->sram_reg); regulator_put(info->sram_reg); } - if (!IS_ERR(info->cpu_clk)) { - clk_disable_unprepare(info->cpu_clk); - clk_put(info->cpu_clk); - } - if (!IS_ERR(info->inter_clk)) { - clk_disable_unprepare(info->inter_clk); - clk_put(info->inter_clk); - } - + clk_disable_unprepare(info->cpu_clk); + clk_put(info->cpu_clk); + clk_disable_unprepare(info->inter_clk); + clk_put(info->inter_clk); dev_pm_opp_of_cpumask_remove_table(&info->cpus); dev_pm_opp_unregister_notifier(info->cpu_dev, &info->opp_nb); } -- 2.39.2