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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Ionela Voinescu <ionela.voinescu@arm.com>,
        Qian Cai <quic_qiancai@quicinc.com>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.12 289/292] cpufreq: CPPC: Fix potential memleak in cppc_cpufreq_cpu_init
Date:   Mon, 19 Jul 2021 16:55:51 +0200
Message-Id: <20210719144952.417634492@linuxfoundation.org>
In-Reply-To: <20210719144942.514164272@linuxfoundation.org>
References: <20210719144942.514164272@linuxfoundation.org>
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From: Viresh Kumar <viresh.kumar@linaro.org>

[ Upstream commit fe2535a44904a77615a3af8e8fd7dafb98fb0e1b ]

It's a classic example of memleak, we allocate something, we fail and
never free the resources.

Make sure we free all resources on policy ->init() failures.

Fixes: a28b2bfc099c ("cppc_cpufreq: replace per-cpu data array with a list")
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com>
Tested-by: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/cpufreq/cppc_cpufreq.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 8a482c434ea6..9ff81e260312 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -182,6 +182,16 @@ static int cppc_verify_policy(struct cpufreq_policy_data *policy)
 	return 0;
 }
 
+static void cppc_cpufreq_put_cpu_data(struct cpufreq_policy *policy)
+{
+	struct cppc_cpudata *cpu_data = policy->driver_data;
+
+	list_del(&cpu_data->node);
+	free_cpumask_var(cpu_data->shared_cpu_map);
+	kfree(cpu_data);
+	policy->driver_data = NULL;
+}
+
 static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
 {
 	struct cppc_cpudata *cpu_data = policy->driver_data;
@@ -196,11 +206,7 @@ static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
 		pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
 			 caps->lowest_perf, cpu, ret);
 
-	/* Remove CPU node from list and free driver data for policy */
-	free_cpumask_var(cpu_data->shared_cpu_map);
-	list_del(&cpu_data->node);
-	kfree(policy->driver_data);
-	policy->driver_data = NULL;
+	cppc_cpufreq_put_cpu_data(policy);
 }
 
 /*
@@ -340,7 +346,8 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	default:
 		pr_debug("Unsupported CPU co-ord type: %d\n",
 			 policy->shared_type);
-		return -EFAULT;
+		ret = -EFAULT;
+		goto out;
 	}
 
 	/*
@@ -355,10 +362,16 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	cpu_data->perf_ctrls.desired_perf =  caps->highest_perf;
 
 	ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
-	if (ret)
+	if (ret) {
 		pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
 			 caps->highest_perf, cpu, ret);
+		goto out;
+	}
 
+	return 0;
+
+out:
+	cppc_cpufreq_put_cpu_data(policy);
 	return ret;
 }
 
-- 
2.30.2