diff options
Diffstat (limited to 'tpm-check-event-log-version-before-reading-final-eve.patch')
| -rw-r--r-- | tpm-check-event-log-version-before-reading-final-eve.patch | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/tpm-check-event-log-version-before-reading-final-eve.patch b/tpm-check-event-log-version-before-reading-final-eve.patch new file mode 100644 index 000000000..9668c807b --- /dev/null +++ b/tpm-check-event-log-version-before-reading-final-eve.patch @@ -0,0 +1,81 @@ +From MAILER-DAEMON Thu May 14 17:38:32 2020 +From: Loïc Yhuel <loic.yhuel@gmail.com> +To: linux-integrity@vger.kernel.org +Cc: matthewgarrett@google.com, ardb@kernel.org, jarkko.sakkinen@linux.intel.com, javierm@redhat.com, Loïc Yhuel <loic.yhuel@gmail.com> +Subject: [PATCH] tpm: check event log version before reading final events +Date: Tue, 12 May 2020 06:01:13 +0200 +Message-Id: <20200512040113.277768-1-loic.yhuel@gmail.com> +Sender: linux-integrity-owner@vger.kernel.org +List-ID: <linux-integrity.vger.kernel.org> +X-Mailing-List: linux-integrity@vger.kernel.org +MIME-Version: 1.0 +Content-Type: text/plain; charset="utf-8" +Content-Transfer-Encoding: 8bit + +This fixes the boot issues since 5.3 on several Dell models when the TPM +is enabled. Depending on the exact grub binary, booting the kernel would +freeze early, or just report an error parsing the final events log. + +We get an event log in the SHA-1 format, which doesn't have a +tcg_efi_specid_event_head in the first event, and there is a final events +table which doesn't match the crypto agile format. +__calc_tpm2_event_size reads bad "count" and "efispecid->num_algs", and +either fails, or loops long enough for the machine to be appear frozen. + +So we now only parse the final events table, which is per the spec always +supposed to be in the crypto agile format, when we got a event log in this +format. + +Fixes: 166a2809d65b2 ("tpm: Don't duplicate events from the final event log in the TCG2 log") +Fixes: c46f3405692de ("tpm: Reserve the TPM final events table") +Signed-off-by: Loïc Yhuel <loic.yhuel@gmail.com> +Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> +Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> +Reviewed-by: Matthew Garrett <mjg59@google.com> +Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1779611 +--- + drivers/firmware/efi/libstub/tpm.c | 5 +++-- + drivers/firmware/efi/tpm.c | 3 ++- + 2 files changed, 5 insertions(+), 3 deletions(-) + +diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c +index 1d59e103a2e3..e9a684637b70 100644 +--- a/drivers/firmware/efi/libstub/tpm.c ++++ b/drivers/firmware/efi/libstub/tpm.c +@@ -54,7 +54,7 @@ void efi_retrieve_tpm2_eventlog(void) + efi_status_t status; + efi_physical_addr_t log_location = 0, log_last_entry = 0; + struct linux_efi_tpm_eventlog *log_tbl = NULL; +- struct efi_tcg2_final_events_table *final_events_table; ++ struct efi_tcg2_final_events_table *final_events_table = NULL; + unsigned long first_entry_addr, last_entry_addr; + size_t log_size, last_entry_size; + efi_bool_t truncated; +@@ -127,7 +127,8 @@ void efi_retrieve_tpm2_eventlog(void) + * Figure out whether any events have already been logged to the + * final events structure, and if so how much space they take up + */ +- final_events_table = get_efi_config_table(LINUX_EFI_TPM_FINAL_LOG_GUID); ++ if (version == EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) ++ final_events_table = get_efi_config_table(LINUX_EFI_TPM_FINAL_LOG_GUID); + if (final_events_table && final_events_table->nr_events) { + struct tcg_pcr_event2_head *header; + int offset; +diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c +index 55b031d2c989..77e101a395e7 100644 +--- a/drivers/firmware/efi/tpm.c ++++ b/drivers/firmware/efi/tpm.c +@@ -62,7 +62,8 @@ int __init efi_tpm_eventlog_init(void) + tbl_size = sizeof(*log_tbl) + log_tbl->size; + memblock_reserve(efi.tpm_log, tbl_size); + +- if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) ++ if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR || ++ log_tbl->version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) + goto out; + + final_tbl = early_memremap(efi.tpm_final_log, sizeof(*final_tbl)); +-- +2.26.2 + + |