cpufreq: CPPC: Fix possible null-ptr-deref for cpufreq_cpu_get_raw()

[PATCH] cpufreq: CPPC: Fix possible null-ptr-deref for cpufreq_cpu_get_raw()

Posted by Jinjie Ruan 1 year, 3 months ago

cpufreq_cpu_get_raw() may return NULL if the cpu is not in
policy->cpus cpu mask and it will cause null pointer dereference.

Fixes: 740fcdc2c20e ("cpufreq: CPPC: Register EM based on efficiency class information")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 drivers/cpufreq/cppc_cpufreq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 2b8708475ac7..01c24c0ee9b3 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -420,6 +420,9 @@ static int cppc_get_cpu_power(struct device *cpu_dev,
 	struct cppc_cpudata *cpu_data;
 
 	policy = cpufreq_cpu_get_raw(cpu_dev->id);
+	if (!policy)
+		return 0;
+
 	cpu_data = policy->driver_data;
 	perf_caps = &cpu_data->perf_caps;
 	max_cap = arch_scale_cpu_capacity(cpu_dev->id);
-- 
2.34.1

Re: [PATCH] cpufreq: CPPC: Fix possible null-ptr-deref for cpufreq_cpu_get_raw()

Posted by Viresh Kumar 1 year, 3 months ago

On 30-10-24, 09:20, Jinjie Ruan wrote:
> cpufreq_cpu_get_raw() may return NULL if the cpu is not in
> policy->cpus cpu mask and it will cause null pointer dereference.
> 
> Fixes: 740fcdc2c20e ("cpufreq: CPPC: Register EM based on efficiency class information")
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
>  drivers/cpufreq/cppc_cpufreq.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
> index 2b8708475ac7..01c24c0ee9b3 100644
> --- a/drivers/cpufreq/cppc_cpufreq.c
> +++ b/drivers/cpufreq/cppc_cpufreq.c
> @@ -420,6 +420,9 @@ static int cppc_get_cpu_power(struct device *cpu_dev,
>  	struct cppc_cpudata *cpu_data;
>  
>  	policy = cpufreq_cpu_get_raw(cpu_dev->id);
> +	if (!policy)
> +		return 0;
> +
>  	cpu_data = policy->driver_data;
>  	perf_caps = &cpu_data->perf_caps;
>  	max_cap = arch_scale_cpu_capacity(cpu_dev->id);

Applied. Thanks.

-- 
viresh