2023-11-21 09:27:17

by Kunwu Chan

Subject: [PATCH] ARM: imx: Check return value of devm_kasprintf in imx_mmdc_perf_init

devm_kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.

Fixes: ebeb49f43c89 ("ARM: imx: Call ida_simple_remove() for ida_simple_get")
Signed-off-by: Kunwu Chan <[email protected]>
---
arch/arm/mach-imx/mmdc.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/arm/mach-imx/mmdc.c b/arch/arm/mach-imx/mmdc.c
index 2157493b78a9..7c471d6a851d 100644
--- a/arch/arm/mach-imx/mmdc.c
+++ b/arch/arm/mach-imx/mmdc.c
@@ -501,6 +501,10 @@ static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_b

name = devm_kasprintf(&pdev->dev,
GFP_KERNEL, "mmdc%d", ret);
+ if (!name) {
+ ret = -ENOMEM;
+ goto pmu_free;
+ }

pmu_mmdc->mmdc_ipg_clk = mmdc_ipg_clk;
pmu_mmdc->devtype_data = (struct fsl_mmdc_devtype_data *)of_id->data;
--
2.34.1

2023-11-21 09:38:38

by Ahmad Fatoum

Subject: Re: [PATCH] ARM: imx: Check return value of devm_kasprintf in imx_mmdc_perf_init

Hello Kunwu,

On 21.11.23 10:25, Kunwu Chan wrote:
> devm_kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure. Ensure the allocation was successful
> by checking the pointer validity.
>
> Fixes: ebeb49f43c89 ("ARM: imx: Call ida_simple_remove() for ida_simple_get")

This commit only moves the allocation around, but it didn't introduce it.
Please reference the first commit that added the allocation.

> Signed-off-by: Kunwu Chan <[email protected]>
> ---
> arch/arm/mach-imx/mmdc.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/arm/mach-imx/mmdc.c b/arch/arm/mach-imx/mmdc.c
> index 2157493b78a9..7c471d6a851d 100644
> --- a/arch/arm/mach-imx/mmdc.c
> +++ b/arch/arm/mach-imx/mmdc.c
> @@ -501,6 +501,10 @@ static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_b
>
> name = devm_kasprintf(&pdev->dev,
> GFP_KERNEL, "mmdc%d", ret);
> + if (!name) {
> + ret = -ENOMEM;
> + goto pmu_free;

Cleanup is incomplete if you goto pmu_free, e.g. ida_simple_remove()
isn't called. pmu_register_err does too much cleanup, so you'll need
to add a new cleanup label.

Cheers,
Ahmad


> + }
>
> pmu_mmdc->mmdc_ipg_clk = mmdc_ipg_clk;
> pmu_mmdc->devtype_data = (struct fsl_mmdc_devtype_data *)of_id->data;

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2023-11-22 06:12:54

by Kunwu Chan

Subject: Re: [PATCH] ARM: imx: Check return value of devm_kasprintf in imx_mmdc_perf_init

Hi,Ahmad

Thank you for your guidance to me
It's my bad, i will update a v2 patch follow your suggestions, and send
it in a new thread.

v2 changes:
1、use the first commit 'e76bdfd7403a' in the 'Fixes' tag.
2、Add new tag 'pmu_release_id' to release the id allocated in
'mmdc_pmu_init', move 'ida_simple_remove(&mmdc_ida, pmu_mmdc->id);' into
'pmu_release_id'.

the v2 patch look like:

+ if (!name) {
+ ret = -ENOMEM;
+ goto pmu_release_id;
+ }

pmu_mmdc->mmdc_ipg_clk = mmdc_ipg_clk;
pmu_mmdc->devtype_data = (struct fsl_mmdc_devtype_data
*)of_id->data;
@@ -523,9 +527,10 @@ static int imx_mmdc_perf_init(struct
platform_device *pdev, void __iomem *mmdc_b

pmu_register_err:
pr_warn("MMDC Perf PMU failed (%d), disabled\n", ret);
- ida_simple_remove(&mmdc_ida, pmu_mmdc->id);
cpuhp_state_remove_instance_nocalls(cpuhp_mmdc_state,
&pmu_mmdc->node);
hrtimer_cancel(&pmu_mmdc->hrtimer);
+pmu_release_id:
+ ida_simple_remove(&mmdc_ida, pmu_mmdc->id);
pmu_free:


Thanks,
Kunwu

On 2023/11/21 17:37, Ahmad Fatoum wrote:
> Hello Kunwu,
>
> On 21.11.23 10:25, Kunwu Chan wrote:
>> devm_kasprintf() returns a pointer to dynamically allocated memory
>> which can be NULL upon failure. Ensure the allocation was successful
>> by checking the pointer validity.
>>
>> Fixes: ebeb49f43c89 ("ARM: imx: Call ida_simple_remove() for ida_simple_get")
>
> This commit only moves the allocation around, but it didn't introduce it.
> Please reference the first commit that added the allocation.
>
>> Signed-off-by: Kunwu Chan <[email protected]>
>> ---
>> arch/arm/mach-imx/mmdc.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/arm/mach-imx/mmdc.c b/arch/arm/mach-imx/mmdc.c
>> index 2157493b78a9..7c471d6a851d 100644
>> --- a/arch/arm/mach-imx/mmdc.c
>> +++ b/arch/arm/mach-imx/mmdc.c
>> @@ -501,6 +501,10 @@ static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_b
>>
>> name = devm_kasprintf(&pdev->dev,
>> GFP_KERNEL, "mmdc%d", ret);
>> + if (!name) {
>> + ret = -ENOMEM;
>> + goto pmu_free;
>
> Cleanup is incomplete if you goto pmu_free, e.g. ida_simple_remove()
> isn't called. pmu_register_err does too much cleanup, so you'll need
> to add a new cleanup label.
>
> Cheers,
> Ahmad
>
>
>> + }
>>
>> pmu_mmdc->mmdc_ipg_clk = mmdc_ipg_clk;
>> pmu_mmdc->devtype_data = (struct fsl_mmdc_devtype_data *)of_id->data;
>