* [PATCH] cpufreq: scpi: Prevent null pointer dereference in scpi_cpufreq_get_rate()
@ 2024-12-30 9:31 Charles Han
2025-01-02 5:00 ` Viresh Kumar
2025-01-02 9:48 ` Sudeep Holla
0 siblings, 2 replies; 3+ messages in thread
From: Charles Han @ 2024-12-30 9:31 UTC (permalink / raw)
To: sudeep.holla, cristian.marussi, rafael, viresh.kumar
Cc: arm-scmi, linux-arm-kernel, linux-pm, linux-kernel, Charles Han
cpufreq_cpu_get_raw() may return NULL if the cpu is not in
policy->cpus cpu mask and it will cause null pointer dereference.
Prevent null pointer dereference in scpi_cpufreq_get_rate().
Fixes: 343a8d17fa8d ("cpufreq: scpi: remove arm_big_little dependency")
Signed-off-by: Charles Han <hanchunchao@inspur.com>
---
drivers/cpufreq/scpi-cpufreq.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
index cd89c1b9832c..c888ed3a0de9 100644
--- a/drivers/cpufreq/scpi-cpufreq.c
+++ b/drivers/cpufreq/scpi-cpufreq.c
@@ -30,6 +30,9 @@ static struct scpi_ops *scpi_ops;
static unsigned int scpi_cpufreq_get_rate(unsigned int cpu)
{
struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
+ if (unlikely(!policy))
+ return 0;
+
struct scpi_data *priv = policy->driver_data;
unsigned long rate = clk_get_rate(priv->clk);
--
2.31.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] cpufreq: scpi: Prevent null pointer dereference in scpi_cpufreq_get_rate()
2024-12-30 9:31 [PATCH] cpufreq: scpi: Prevent null pointer dereference in scpi_cpufreq_get_rate() Charles Han
@ 2025-01-02 5:00 ` Viresh Kumar
2025-01-02 9:48 ` Sudeep Holla
1 sibling, 0 replies; 3+ messages in thread
From: Viresh Kumar @ 2025-01-02 5:00 UTC (permalink / raw)
To: Charles Han
Cc: sudeep.holla, cristian.marussi, rafael, arm-scmi,
linux-arm-kernel, linux-pm, linux-kernel
On 30-12-24, 17:31, Charles Han 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.
> Prevent null pointer dereference in scpi_cpufreq_get_rate().
>
> Fixes: 343a8d17fa8d ("cpufreq: scpi: remove arm_big_little dependency")
> Signed-off-by: Charles Han <hanchunchao@inspur.com>
> ---
> drivers/cpufreq/scpi-cpufreq.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
> index cd89c1b9832c..c888ed3a0de9 100644
> --- a/drivers/cpufreq/scpi-cpufreq.c
> +++ b/drivers/cpufreq/scpi-cpufreq.c
> @@ -30,6 +30,9 @@ static struct scpi_ops *scpi_ops;
> static unsigned int scpi_cpufreq_get_rate(unsigned int cpu)
> {
> struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
> + if (unlikely(!policy))
> + return 0;
> +
> struct scpi_data *priv = policy->driver_data;
> unsigned long rate = clk_get_rate(priv->clk);
The check needs to be made after all the variable definitions.
--
viresh
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] cpufreq: scpi: Prevent null pointer dereference in scpi_cpufreq_get_rate()
2024-12-30 9:31 [PATCH] cpufreq: scpi: Prevent null pointer dereference in scpi_cpufreq_get_rate() Charles Han
2025-01-02 5:00 ` Viresh Kumar
@ 2025-01-02 9:48 ` Sudeep Holla
1 sibling, 0 replies; 3+ messages in thread
From: Sudeep Holla @ 2025-01-02 9:48 UTC (permalink / raw)
To: Charles Han
Cc: cristian.marussi, rafael, Sudeep Holla, viresh.kumar, arm-scmi,
linux-arm-kernel, linux-pm, linux-kernel
On Mon, Dec 30, 2024 at 05:31:59PM +0800, Charles Han 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.
> Prevent null pointer dereference in scpi_cpufreq_get_rate().
>
Can you please fix such occurrences in other places too ?
I see it in apple-soc-cpufreq.c and scmi-cpufreq.c as well.
> Fixes: 343a8d17fa8d ("cpufreq: scpi: remove arm_big_little dependency")
> Signed-off-by: Charles Han <hanchunchao@inspur.com>
> ---
> drivers/cpufreq/scpi-cpufreq.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
> index cd89c1b9832c..c888ed3a0de9 100644
> --- a/drivers/cpufreq/scpi-cpufreq.c
> +++ b/drivers/cpufreq/scpi-cpufreq.c
> @@ -30,6 +30,9 @@ static struct scpi_ops *scpi_ops;
> static unsigned int scpi_cpufreq_get_rate(unsigned int cpu)
> {
> struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
> + if (unlikely(!policy))
> + return 0;
> +
> struct scpi_data *priv = policy->driver_data;
> unsigned long rate = clk_get_rate(priv->clk);
>
--
Regards,
Sudeep
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-12-30 9:31 [PATCH] cpufreq: scpi: Prevent null pointer dereference in scpi_cpufreq_get_rate() Charles Han
2025-01-02 5:00 ` Viresh Kumar
2025-01-02 9:48 ` Sudeep Holla
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