[PATCH -next] staging: greybus: camera: Switch to memdup_user_nul()

[PATCH -next] staging: greybus: camera: Switch to memdup_user_nul()

[Yang Yingliang]

Use memdup_user_nul() helper instead of open-coding to
simplify the code.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/staging/greybus/camera.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/greybus/camera.c b/drivers/staging/greybus/camera.c
index b570e13394ac..0f005facffbc 100644
--- a/drivers/staging/greybus/camera.c
+++ b/drivers/staging/greybus/camera.c
@@ -1120,16 +1120,10 @@ static ssize_t gb_camera_debugfs_write(struct file *file,
 	if (len > 1024)
 		return -EINVAL;
 
-	kbuf = kmalloc(len + 1, GFP_KERNEL);
-	if (!kbuf)
+	kbuf = memdup_user_nul(buf, len);
+	if (IS_ERR(kbuf))
 		return -ENOMEM;
 
-	if (copy_from_user(kbuf, buf, len)) {
-		ret = -EFAULT;
-		goto done;
-	}
-
-	kbuf[len] = '\0';
 
 	ret = op->execute(gcam, kbuf, len);
 
-- 
2.25.1

Re: [PATCH -next] staging: greybus: camera: Switch to memdup_user_nul()

[Dan Carpenter]

On Wed, Mar 31, 2021 at 05:52:01PM +0800, Yang Yingliang wrote:
> Use memdup_user_nul() helper instead of open-coding to
> simplify the code.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
>  drivers/staging/greybus/camera.c | 10 ++--------
>  1 file changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/staging/greybus/camera.c b/drivers/staging/greybus/camera.c
> index b570e13394ac..0f005facffbc 100644
> --- a/drivers/staging/greybus/camera.c
> +++ b/drivers/staging/greybus/camera.c
> @@ -1120,16 +1120,10 @@ static ssize_t gb_camera_debugfs_write(struct file *file,
>  	if (len > 1024)
>  		return -EINVAL;
>  
> -	kbuf = kmalloc(len + 1, GFP_KERNEL);
> -	if (!kbuf)
> +	kbuf = memdup_user_nul(buf, len);
> +	if (IS_ERR(kbuf))
>  		return -ENOMEM;

return PTR_ERR(kbuf);

>  
> -	if (copy_from_user(kbuf, buf, len)) {
> -		ret = -EFAULT;
> -		goto done;
> -	}
> -
> -	kbuf[len] = '\0';
>  
   ^^^^^^^^
Please delete this blank line so there aren't two blank lines in a row.

>  	ret = op->execute(gcam, kbuf, len);

regards,
dan carpenter

Re: [PATCH -next] staging: greybus: camera: Switch to memdup_user_nul()

[Yang Yingliang]

Hi,

On 2021/3/31 18:24, Dan Carpenter wrote:
> On Wed, Mar 31, 2021 at 05:52:01PM +0800, Yang Yingliang wrote:
>> Use memdup_user_nul() helper instead of open-coding to
>> simplify the code.
>>
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
>> ---
>>   drivers/staging/greybus/camera.c | 10 ++--------
>>   1 file changed, 2 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/staging/greybus/camera.c b/drivers/staging/greybus/camera.c
>> index b570e13394ac..0f005facffbc 100644
>> --- a/drivers/staging/greybus/camera.c
>> +++ b/drivers/staging/greybus/camera.c
>> @@ -1120,16 +1120,10 @@ static ssize_t gb_camera_debugfs_write(struct file *file,
>>   	if (len > 1024)
>>   		return -EINVAL;
>>   
>> -	kbuf = kmalloc(len + 1, GFP_KERNEL);
>> -	if (!kbuf)
>> +	kbuf = memdup_user_nul(buf, len);
>> +	if (IS_ERR(kbuf))
>>   		return -ENOMEM;
> return PTR_ERR(kbuf);
>
>>   
>> -	if (copy_from_user(kbuf, buf, len)) {
>> -		ret = -EFAULT;
>> -		goto done;
>> -	}
>> -
>> -	kbuf[len] = '\0';
>>   
>     ^^^^^^^^
> Please delete this blank line so there aren't two blank lines in a row.

I will change it and send a v2.

Thanks,

Yang

>
>>   	ret = op->execute(gcam, kbuf, len);
> regards,
> dan carpenter
>
> .