Re: [PATCH v2 5/9] platform/x86/intel/ifs: Validate image size

[Ilpo Järvinen]

On Fri, 22 Sep 2023, Jithu Joseph wrote:

> Perform additional validation prior to loading IFS image.
> 
> Error out if the size of the file being loaded doesn't match the size
> specified in the header.
> 
> Signed-off-by: Jithu Joseph <jithu.joseph@xxxxxxxxx>
> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
> Tested-by: Pengfei Xu <pengfei.xu@xxxxxxxxx>
> ---
>  drivers/platform/x86/intel/ifs/load.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
> index 6b827247945b..b09106034fac 100644
> --- a/drivers/platform/x86/intel/ifs/load.c
> +++ b/drivers/platform/x86/intel/ifs/load.c
> @@ -375,6 +375,7 @@ int ifs_load_firmware(struct device *dev)
>  {
>  	const struct ifs_test_caps *test = ifs_get_test_caps(dev);
>  	struct ifs_data *ifsd = ifs_get_data(dev);
> +	unsigned int expected_size;
>  	const struct firmware *fw;
>  	char scan_path[64];
>  	int ret = -EINVAL;
> @@ -389,6 +390,13 @@ int ifs_load_firmware(struct device *dev)
>  		goto done;
>  	}
>  
> +	expected_size = ((struct microcode_header_intel *)fw->data)->totalsize;
> +	if (fw->size != expected_size) {
> +		dev_err(dev, "File size mismatch (expected %d, actual %ld). Corrupted IFS image.\n",
> +			expected_size, fw->size);
> +		return -EBADFD;

I don't think this error code is best suited for what occurred. I guess 
returning just -EINVAL would be fine.

-- 
 i.

> +	}
> +
>  	ret = image_sanity_check(dev, (struct microcode_header_intel *)fw->data);
>  	if (ret)
>  		goto release;
>