pinctrl: berlin: fix 'pctrl->functions' allocation in berlin_pinctrl_build_state

Message ID 20180731142501.21888-1-yuehaibing@huawei.com
State New
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Series
  • pinctrl: berlin: fix 'pctrl->functions' allocation in berlin_pinctrl_build_state
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Commit Message

YueHaibing July 31, 2018, 2:25 p.m.
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 <yuehaibing@huawei.com>
---
 drivers/pinctrl/berlin/berlin.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

Comments

Jisheng Zhang Aug. 1, 2018, 2:36 a.m. | #1
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 <yuehaibing@huawei.com>
> ---
>  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;

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YueHaibing Aug. 1, 2018, 4:12 a.m. | #2
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 <yuehaibing@huawei.com>
>> ---
>>  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;
> 
> 
> 

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Patch

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;