ACK: [PATCH] efi_runtime: use memdup_user() as a cleanup

[Colin Ian King]

On 14/09/16 08:31, Ivan Hu wrote:
> Got warning when upstreaming efi_runtime driver
> 
> drivers/firmware/efi/test/efi_test.c:269:8-15: WARNING opportunity for
> memdup_user
> 
> Use memdup_user rather than duplicating its implementation
> This is a little bit restricted to reduce false positives
> 
> Generated by: coccinelle/api/memdup_user.coc
> 
> Signed-off-by: Ivan Hu <ivan.hu at canonical.com>
> ---
>  efi_runtime/efi_runtime.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/efi_runtime/efi_runtime.c b/efi_runtime/efi_runtime.c
> index 594eccd..19f8103 100644
> --- a/efi_runtime/efi_runtime.c
> +++ b/efi_runtime/efi_runtime.c
> @@ -284,14 +284,10 @@ static long efi_runtime_set_variable(unsigned long arg)
>  			return rv;
>  	}
>  
> -	data = kmalloc(setvariable.data_size, GFP_KERNEL);
> -	if (!data) {
> +	data = memdup_user(setvariable.data, setvariable.data_size);
> +	if (IS_ERR(data)) {
>  		kfree(name);
> -		return -ENOMEM;
> -	}
> -	if (copy_from_user(data, setvariable.data, setvariable.data_size)) {
> -		rv = -EFAULT;
> -		goto out;
> +		return PTR_ERR(data);
>  	}
>  
>  	status = efi.set_variable(name, &vendor_guid,
> 
memdup_user was added to the kernel in 2009, so I guess this works fine
for all our supported releases.

Acked-by: Colin Ian King <colin.king at canonical.com>