On Tue, Nov 06, 2018 at 04:01:55PM +0100, Roberto Sassu wrote:
> tcg_efi_specid_event and tcg_pcr_event2 declaration contains static arrays
> for a list of hash algorithms used for event logs and event log digests.
> However, according to TCG EFI Protocol Specification, these arrays have
> variable sizes and are not suitable for parsing events with type casting.
>
> Since declaring static arrays with hard-coded sizes does not help to parse
> data after these arrays, this patch removes the declaration of
> TPM2_ACTIVE_PCR_BANKS and sets the size of the arrays above to zero.
>
> Fixes: 4d23cc323cdb ("tpm: add securityfs support for TPM 2.0 firmware
> event log")
>
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h
> index 20d9da77fc11..3d5d162f09cc 100644
> --- a/include/linux/tpm_eventlog.h
> +++ b/include/linux/tpm_eventlog.h
> @@ -8,7 +8,6 @@
> #define TCG_EVENT_NAME_LEN_MAX 255
> #define MAX_TEXT_EVENT 1000 /* Max event string length */
> #define ACPI_TCPA_SIG "TCPA" /* 0x41504354 /'TCPA' */
> -#define TPM2_ACTIVE_PCR_BANKS 3
>
> #define EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2 0x1
> #define EFI_TCG2_EVENT_LOG_FORMAT_TCG_2 0x2
> @@ -90,7 +89,7 @@ struct tcg_efi_specid_event {
> u8 spec_errata;
> u8 uintnsize;
> u32 num_algs;
> - struct tcg_efi_specid_event_algs digest_sizes[TPM2_ACTIVE_PCR_BANKS];
> + struct tcg_efi_specid_event_algs digest_sizes[0];
> u8 vendor_info_size;
> u8 vendor_info[0];
> } __packed;
> @@ -117,7 +116,7 @@ struct tcg_pcr_event2 {
> u32 pcr_idx;
> u32 event_type;
> u32 count;
> - struct tpm2_digest digests[TPM2_ACTIVE_PCR_BANKS];
> + struct tpm2_digest digests[0];
> struct tcg_event_field event;
> } __packed;
>
> --
> 2.17.1
>
I somehow lost your response but what you must do is to explain why is
it OK for last two fields to overlap.
/Jarkko
