2018-07-31 14:27:45

by Yue Haibing

Subject: [PATCH] pinctrl: berlin: fix 'pctrl->functions' allocation in berlin_pinctrl_build_state

fixes following Smatch static check warning:

drivers/pinctrl/berlin/berlin.c:237 berlin_pinctrl_build_state()
warn: passing devm_ allocated variable to kfree. 'pctrl->functions'

As we will be calling krealloc() on pointer 'pctrl->functions', which means
kfree() will be called in there, devm_kzalloc() shouldn't be used with
the allocation in the first place. Fix the warning by calling kcalloc()
and managing the free procedure in error path on our own.

Fixes: 3de68d331c24 ("pinctrl: berlin: add the core pinctrl driver for Marvell Berlin SoCs")
Signed-off-by: YueHaibing <[email protected]>
---
drivers/pinctrl/berlin/berlin.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/berlin/berlin.c b/drivers/pinctrl/berlin/berlin.c
index d6d183e..db2afb2 100644
--- a/drivers/pinctrl/berlin/berlin.c
+++ b/drivers/pinctrl/berlin/berlin.c
@@ -216,10 +216,8 @@ static int berlin_pinctrl_build_state(struct platform_device *pdev)
}

/* we will reallocate later */
- pctrl->functions = devm_kcalloc(&pdev->dev,
- max_functions,
- sizeof(*pctrl->functions),
- GFP_KERNEL);
+ pctrl->functions = kcalloc(max_functions,
+ sizeof(*pctrl->functions), GFP_KERNEL);
if (!pctrl->functions)
return -ENOMEM;

@@ -257,8 +255,10 @@ static int berlin_pinctrl_build_state(struct platform_device *pdev)
function++;
}

- if (!found)
+ if (!found) {
+ kfree(function);
return -EINVAL;
+ }

if (!function->groups) {
function->groups =
@@ -267,8 +267,10 @@ static int berlin_pinctrl_build_state(struct platform_device *pdev)
sizeof(char *),
GFP_KERNEL);

- if (!function->groups)
+ if (!function->groups) {
+ kfree(function);
return -ENOMEM;
+ }
}

groups = function->groups;
--
2.7.0

2018-08-01 02:42:18

by Jisheng Zhang

Subject: Re: [PATCH] pinctrl: berlin: fix 'pctrl->functions' allocation in berlin_pinctrl_build_state

Hi,

On Tue, 31 Jul 2018 22:25:01 +0800 YueHaibing wrote:

> fixes following Smatch static check warning:
>
> drivers/pinctrl/berlin/berlin.c:237 berlin_pinctrl_build_state()
> warn: passing devm_ allocated variable to kfree. 'pctrl->functions'
>
> As we will be calling krealloc() on pointer 'pctrl->functions', which means
> kfree() will be called in there, devm_kzalloc() shouldn't be used with
> the allocation in the first place. Fix the warning by calling kcalloc()
> and managing the free procedure in error path on our own.

Good catch. Comments below.

>
> Fixes: 3de68d331c24 ("pinctrl: berlin: add the core pinctrl driver for Marvell Berlin SoCs")
> Signed-off-by: YueHaibing <[email protected]>
> ---
> drivers/pinctrl/berlin/berlin.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pinctrl/berlin/berlin.c b/drivers/pinctrl/berlin/berlin.c
> index d6d183e..db2afb2 100644
> --- a/drivers/pinctrl/berlin/berlin.c
> +++ b/drivers/pinctrl/berlin/berlin.c
> @@ -216,10 +216,8 @@ static int berlin_pinctrl_build_state(struct platform_device *pdev)
> }
>
> /* we will reallocate later */
> - pctrl->functions = devm_kcalloc(&pdev->dev,
> - max_functions,
> - sizeof(*pctrl->functions),
> - GFP_KERNEL);
> + pctrl->functions = kcalloc(max_functions,
> + sizeof(*pctrl->functions), GFP_KERNEL);
> if (!pctrl->functions)
> return -ENOMEM;
>
> @@ -257,8 +255,10 @@ static int berlin_pinctrl_build_state(struct platform_device *pdev)
> function++;
> }
>
> - if (!found)
> + if (!found) {
> + kfree(function);

is it enough to just free one function? I think we need to free functions.

> return -EINVAL;
> + }
>
> if (!function->groups) {
> function->groups =
> @@ -267,8 +267,10 @@ static int berlin_pinctrl_build_state(struct platform_device *pdev)
> sizeof(char *),
> GFP_KERNEL);
>
> - if (!function->groups)
> + if (!function->groups) {
> + kfree(function);

ditto

> return -ENOMEM;
> + }
> }
>
> groups = function->groups;

2018-08-01 04:14:25

by Yue Haibing

Subject: Re: [PATCH] pinctrl: berlin: fix 'pctrl->functions' allocation in berlin_pinctrl_build_state

On 2018/8/1 10:36, Jisheng Zhang wrote:
> Hi,
>
> On Tue, 31 Jul 2018 22:25:01 +0800 YueHaibing wrote:
>
>> fixes following Smatch static check warning:
>>
>> drivers/pinctrl/berlin/berlin.c:237 berlin_pinctrl_build_state()
>> warn: passing devm_ allocated variable to kfree. 'pctrl->functions'
>>
>> As we will be calling krealloc() on pointer 'pctrl->functions', which means
>> kfree() will be called in there, devm_kzalloc() shouldn't be used with
>> the allocation in the first place. Fix the warning by calling kcalloc()
>> and managing the free procedure in error path on our own.
>
> Good catch. Comments below.
>
>>
>> Fixes: 3de68d331c24 ("pinctrl: berlin: add the core pinctrl driver for Marvell Berlin SoCs")
>> Signed-off-by: YueHaibing <[email protected]>
>> ---
>> drivers/pinctrl/berlin/berlin.c | 14 ++++++++------
>> 1 file changed, 8 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/pinctrl/berlin/berlin.c b/drivers/pinctrl/berlin/berlin.c
>> index d6d183e..db2afb2 100644
>> --- a/drivers/pinctrl/berlin/berlin.c
>> +++ b/drivers/pinctrl/berlin/berlin.c
>> @@ -216,10 +216,8 @@ static int berlin_pinctrl_build_state(struct platform_device *pdev)
>> }
>>
>> /* we will reallocate later */
>> - pctrl->functions = devm_kcalloc(&pdev->dev,
>> - max_functions,
>> - sizeof(*pctrl->functions),
>> - GFP_KERNEL);
>> + pctrl->functions = kcalloc(max_functions,
>> + sizeof(*pctrl->functions), GFP_KERNEL);
>> if (!pctrl->functions)
>> return -ENOMEM;
>>
>> @@ -257,8 +255,10 @@ static int berlin_pinctrl_build_state(struct platform_device *pdev)
>> function++;
>> }
>>
>> - if (!found)
>> + if (!found) {
>> + kfree(function);
>
> is it enough to just free one function? I think we need to free functions.

Yep, should free 'pctrl->functions', Thanks!

Will send v2.

>
>> return -EINVAL;
>> + }
>>
>> if (!function->groups) {
>> function->groups =
>> @@ -267,8 +267,10 @@ static int berlin_pinctrl_build_state(struct platform_device *pdev)
>> sizeof(char *),
>> GFP_KERNEL);
>>
>> - if (!function->groups)
>> + if (!function->groups) {
>> + kfree(function);
>
> ditto
>
>> return -ENOMEM;
>> + }
>> }
>>
>> groups = function->groups;
>
>
>