Re: [PATCH v2] cpufreq: kryo: Fix possible error code dereference

From: Viresh Kumar
Date: Mon Jun 18 2018 - 00:55:33 EST


On 17-06-18, 21:58, ilia.lin@xxxxxxxxx wrote:
> From: Ilia Lin <ilia.lin@xxxxxxxxx>
>
> In event of error returned by the nvmem_cell_read() non-pointer value
> may be dereferenced. Fix this with error handling.
> Additionally free the allocated speedbin buffer, as per the API.
>
> Fixes: 9ce36edd1a52 (cpufreq: Add Kryo CPU scaling driver)
> Signed-off-by: Ilia Lin <ilia.lin@xxxxxxxxx>
> ---
> drivers/cpufreq/qcom-cpufreq-kryo.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/cpufreq/qcom-cpufreq-kryo.c b/drivers/cpufreq/qcom-cpufreq-kryo.c
> index d049fe4b80c4..74b9b93d511b 100644
> --- a/drivers/cpufreq/qcom-cpufreq-kryo.c
> +++ b/drivers/cpufreq/qcom-cpufreq-kryo.c
> @@ -115,6 +115,8 @@ static int qcom_cpufreq_kryo_probe(struct platform_device *pdev)
>
> speedbin = nvmem_cell_read(speedbin_nvmem, &len);
> nvmem_cell_put(speedbin_nvmem);
> + if (IS_ERR(speedbin))
> + return PTR_ERR(speedbin);
>
> switch (msm8996_version) {
> case MSM8996_V3:
> @@ -127,6 +129,7 @@ static int qcom_cpufreq_kryo_probe(struct platform_device *pdev)
> BUG();
> break;
> }
> + kfree(speedbin);
>
> for_each_possible_cpu(cpu) {
> cpu_dev = get_cpu_device(cpu);

Ideally this should have been two patches as you were fixing two
different problems. But anyway, you can go through this time.

Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

--
viresh