[PATCH] efi_loader: fixe unreachable statement in efi_sigstore_parse_siglist

[Heinrich Schuchardt]

On 4/21/20 2:38 AM, AKASHI Takahiro wrote:
> "if (left < esl->signature_size)" is not reachable in a while loop.
> But it is still valuable in case that a given signature database is
> somehow corrupted. So fix the while loop condition.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> Reported-by: Heinrich Schuchardt <xypron.glpk at gmx.de>

Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>

> ---
>  lib/efi_loader/efi_signature.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/efi_loader/efi_signature.c b/lib/efi_loader/efi_signature.c
> index 0ead10203aeb..b392e72fefcd 100644
> --- a/lib/efi_loader/efi_signature.c
> +++ b/lib/efi_loader/efi_signature.c
> @@ -668,7 +668,7 @@ efi_sigstore_parse_siglist(struct efi_signature_list *esl)
>  	esd = (struct efi_signature_data *)
>  			((u8 *)esl + sizeof(*esl) + esl->signature_header_size);
>
> -	while ((left > 0) && left >= esl->signature_size) {
> +	while (left > 0) {
>  		/* Signature must exist if there is remaining data. */
>  		if (left < esl->signature_size) {
>  			debug("Certificate is too small\n");
>