| Message ID | 20181106150159.1136-3-roberto.sassu@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tpm: retrieve digest size of unknown algorithms from TPM | expand |
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@huawei.com> > --- > include/linux/tpm_eventlog.h | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > 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; Last two fields make sense at least without comment as they overlap. > } __packed; > > -- > 2.17.1 > /Jarkko
On Thu, Nov 08, 2018 at 04:02:08PM +0200, Jarkko Sakkinen wrote: > 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@huawei.com> > > --- > > include/linux/tpm_eventlog.h | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > 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; > > Last two fields make sense at least without comment as they overlap. i.e. would be semantically equal to union { struct tpm2_digest digests[0]; struct tcg_event_field event; }; /Jarkko
On 11/8/2018 3:03 PM, Jarkko Sakkinen wrote: > On Thu, Nov 08, 2018 at 04:02:08PM +0200, Jarkko Sakkinen wrote: >> 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@huawei.com> >>> --- >>> include/linux/tpm_eventlog.h | 5 ++--- >>> 1 file changed, 2 insertions(+), 3 deletions(-) >>> >>> 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; >> >> Last two fields make sense at least without comment as they overlap. > > i.e. would be semantically equal to > > union { > struct tpm2_digest digests[0]; > struct tcg_event_field event; > }; I didn't understand. Should I add the union? Roberto > /Jarkko >
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@huawei.com> > 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
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;
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@huawei.com> --- include/linux/tpm_eventlog.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)