[PATCH 5.12 289/292] cpufreq: CPPC: Fix potential memleak in cppc_cpufreq_cpu_init

Greg Kroah-Hartman
2021-07-19T18:20:35Z

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