> diff --git a/security/integrity/ima/ima_crypto.c
> b/security/integrity/ima/ima_crypto.c
> index 6f5696d999d0..a43080fb8edc 100644
> --- a/security/integrity/ima/ima_crypto.c
> +++ b/security/integrity/ima/ima_crypto.c
> @@ -625,26 +625,43 @@ int ima_calc_field_array_hash(struct ima_field_data
> *field_data,
> u16 alg_id;
> int rc, i;
>
> +#if IS_ENABLED(CONFIG_IMA_COMPAT_FALLBACK_TPM_EXTEND)
> rc = ima_calc_field_array_hash_tfm(field_data, entry, ima_sha1_idx);
> if (rc)
> return rc;
>
> entry->digests[ima_sha1_idx].alg_id = TPM_ALG_SHA1;
> +#endif
>
> for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) {
> +#if IS_ENABLED(CONFIG_IMA_COMPAT_FALLBACK_TPM_EXTEND)
> if (i == ima_sha1_idx)
> continue;
> +#endif
>
> if (i < NR_BANKS(ima_tpm_chip)) {
> alg_id = ima_tpm_chip->allocated_banks[i].alg_id;
> entry->digests[i].alg_id = alg_id;
> }
>
> - /* for unmapped TPM algorithms digest is still a padded SHA1 */
> + /*
> + * For unmapped TPM algorithms, the digest is still a
> + * padded SHA1 if backwards-compatibility fallback PCR
> + * extension is enabled. Otherwise fill with
> + * 0xfes. This is the value to invalidate unsupported
> + * PCR banks with. Also, a non-all-zeroes value serves
> + * as an indicator to kexec measurement restoration
> + * that the entry is not a violation and all its
> + * template digests need to get recomputed.
> + */
> if (!ima_algo_array[i].tfm) {
> +#if IS_ENABLED(CONFIG_IMA_COMPAT_FALLBACK_TPM_EXTEND)
> memcpy(entry->digests[i].digest,
> entry->digests[ima_sha1_idx].digest,
> TPM_DIGEST_SIZE);
> +#else
> + memset(entry->digests[i].digest, 0xfe, TPM_DIGEST_SIZE);
> +#endif
Using TPM_DIGEST_SIZE will result in a padded 0xfe value.
> continue;
> }
>
