efi_loader: efi_variable_parse_signature() returns NULL on error

AKASHI Takahiro
2020-05-07T07:14:18Z

On Thu, May 07, 2020 at 02:13:18AM +0200, Patrick Wildt wrote:
> efi_variable_parse_signature() returns NULL on error, so IS_NULL()
> is an incorrect check. The goto err leads to pkcs7_free_message(),
> which works fine on a NULL ptr.
>
> Signed-off-by: Patrick Wildt <patrick@blueri.se>

Reviewed-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
>
> diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
> index 58f8fae358..c5fe896de2 100644
> --- a/lib/efi_loader/efi_variable.c
> +++ b/lib/efi_loader/efi_variable.c
> @@ -519,9 +519,8 @@ static efi_status_t efi_variable_authenticate(u16 *variable,
> var_sig = efi_variable_parse_signature(auth->auth_info.cert_data,
> auth->auth_info.hdr.dwLength
> - sizeof(auth->auth_info));
> - if (IS_ERR(var_sig)) {
> + if (!var_sig) {
> debug("Parsing variable's signature failed\n");
> - var_sig = NULL;
> goto err;
> }
>