From patchwork Wed Jun 5 18:05:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 10977461 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 58AE56C5 for ; Wed, 5 Jun 2019 18:05:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3F3CE2675C for ; Wed, 5 Jun 2019 18:05:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 33B3F26253; Wed, 5 Jun 2019 18:05:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7965C26253 for ; Wed, 5 Jun 2019 18:05:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726477AbfFESFU (ORCPT ); Wed, 5 Jun 2019 14:05:20 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:36686 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726421AbfFESFU (ORCPT ); Wed, 5 Jun 2019 14:05:20 -0400 Received: by mail-qt1-f201.google.com with SMTP id q26so5216634qtr.3 for ; Wed, 05 Jun 2019 11:05:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=+LvoH0vaLRnePydTNhqA6OqqBmdGXoMJcCKR6797hFQ=; b=GI/SWdiSaQbOR4mrG9Kg3VbxJ6uZytM7SVpwZzfdTlrqCQ8aLY+Rs1DQ7XcvOYK3uY tIupQWgSBvUjITwvIBMA8PxuPqfQp7Vf1e7aWqlFXWIT6D9zUyc86Xpv9+HBv9hRKACz X1gE4ocEV5whME9fTRKeAfyquH+G5doLzRI9PNhWI7VgVWVRARFA3rGxLFETBIh/ewHI 0pwxn47kUxBRAImPDcretyZFTAgfU4W2lv51nnEWlml9V7RilkVrZBkIpfEROWHry2T4 uq3KZLfdFKuLj102ngL9JvRzzmZy4TBHbLFHhpF4/f0An8QFTPfPrLS9n3hDt6nsa7MQ ME9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=+LvoH0vaLRnePydTNhqA6OqqBmdGXoMJcCKR6797hFQ=; b=DiB1CVTw9LoWG0sq4j8jdJELr/Fub/tv8amAoUNh1TYiOQ4Ju/oB5+Vaz1gkN/8z2J LfSiuDUkUxS7neg9tVkMVm/xMN0eLrJJ8Otue5psu5NEFZ4yp6s2sNnb1ZTDB8pCn2vQ wJGtbdanT6yWnxRMnAOcuHWImd7IdJuU0xP70pmv73bp/bYtyNuB9Cp7N+w6jGEr0ilW fqDzUfQNV92bRZ+RtMVmfRLeUqTTh53+f2I6E5ekmX0xHPURcH6esF1xUeJQ/SP1/Qz9 a92qYv+NXeRsRUbBCesmdn/lsJI5X82w7H6cHFQ6jprc7a760LhRA2AHPqs2afmVYOyX DAMA== X-Gm-Message-State: APjAAAXfIa9z1HPpC6gtHSC5YZVnFKQS4hqNMMoJpyHz6L6R5nzb3MHc o6bUy0rc1gTifAqZi9gcyhgzDBf7kzs8RSSZuaLT+tWAAqo2ZLFl7qX2zEGwXjBKW/z2COMiHBP ooFzDvcg0S0wS/lA1VVyjvo9Sf0d5bXASy+zzkhsExsr85zao2sfKvIU7SABS5EjP/fKMN0DTCu k5YA1/4KG2l67ujTEl0T8= X-Google-Smtp-Source: APXvYqyksZIhrUJc38DSHALKwApuiScIJLZgzn8zqF/heWaHISO0px+6Y2KLEBPpVEP+3vGfiJugqEMdiBQGmJ2gPaU+/w== X-Received: by 2002:a0c:d78c:: with SMTP id z12mr1336627qvi.244.1559757918947; Wed, 05 Jun 2019 11:05:18 -0700 (PDT) Date: Wed, 5 Jun 2019 11:05:15 -0700 Message-Id: <20190605180515.25326-1-matthewgarrett@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.22.0.rc1.311.g5d7573a151-goog Subject: [PATCH V2] tpm: Don't duplicate events from the final event log in the TCG2 log From: Matthew Garrett To: linux-integrity@vger.kernel.org Cc: peterhuewe@gmx.de, jarkko.sakkinen@linux.intel.com, jgg@ziepe.ca, linux-efi@vger.kernel.org, ard.biesheuvel@linaro.org, Matthew Garrett , Matthew Garrett , Joe Richey Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP After the first call to GetEventLog() on UEFI systems using the TCG2 crypto agile log format, any further log events (other than those triggered by ExitBootServices()) will be logged in both the main log and also in the Final Events Log. While the kernel only calls GetEventLog() immediately before ExitBootServices(), we can't control whether earlier parts of the boot process have done so. This will result in log entries that exist in both logs, and so the current approach of simply appending the Final Event Log to the main log will result in events being duplicated. We can avoid this problem by looking at the size of the Final Event Log just before we call ExitBootServices() and exporting this to the main kernel. The kernel can then skip over all events that occured before ExitBootServices() and only append events that were not also logged to the main log. Signed-off-by: Matthew Garrett Reported-by: Joe Richey Suggested-by: Joe Richey Reviewed-by: Jarkko Sakkinen --- Unmodified other than changing the name of final_events_early_size to final_events_preboot_size. drivers/char/tpm/eventlog/efi.c | 11 ++++++- .../firmware/efi/libstub/efi-stub-helper.c | 15 ++++++++++ drivers/firmware/efi/libstub/efistub.h | 2 ++ drivers/firmware/efi/libstub/fdt.c | 27 ++++++----------- drivers/firmware/efi/libstub/tpm.c | 30 +++++++++++++++++++ drivers/firmware/efi/tpm.c | 2 +- include/linux/efi.h | 1 + 7 files changed, 68 insertions(+), 20 deletions(-) diff --git a/drivers/char/tpm/eventlog/efi.c b/drivers/char/tpm/eventlog/efi.c index 9179cf6bdee9..be6540f2cb3d 100644 --- a/drivers/char/tpm/eventlog/efi.c +++ b/drivers/char/tpm/eventlog/efi.c @@ -80,6 +80,8 @@ int tpm_read_log_efi(struct tpm_chip *chip) goto out; } + efi_tpm_final_log_size -= log_tbl->final_events_preboot_size; + tmp = krealloc(log->bios_event_log, log_size + efi_tpm_final_log_size, GFP_KERNEL); @@ -90,8 +92,15 @@ int tpm_read_log_efi(struct tpm_chip *chip) } log->bios_event_log = tmp; + + /* + * Copy any of the final events log that didn't also end up in the + * main log. Events can be logged in both if events are generated + * between GetEventLog() and ExitBootServices(). + */ memcpy((void *)log->bios_event_log + log_size, - final_tbl->events, efi_tpm_final_log_size); + final_tbl->events + log_tbl->final_events_preboot_size, + efi_tpm_final_log_size); log->bios_event_log_end = log->bios_event_log + log_size + efi_tpm_final_log_size; diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index e4610e72b78f..1db780c0f07b 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -926,3 +926,18 @@ efi_status_t efi_exit_boot_services(efi_system_table_t *sys_table_arg, fail: return status; } + +void *get_efi_config_table(efi_system_table_t *sys_table, efi_guid_t guid) +{ + efi_config_table_t *tables = (efi_config_table_t *)sys_table->tables; + int i; + + for (i = 0; i < sys_table->nr_tables; i++) { + if (efi_guidcmp(tables[i].guid, guid) != 0) + continue; + + return (void *)tables[i].table; + } + + return NULL; +} diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 1b1dfcaa6fb9..7f1556fd867d 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -65,6 +65,8 @@ efi_status_t check_platform_features(efi_system_table_t *sys_table_arg); efi_status_t efi_random_get_seed(efi_system_table_t *sys_table_arg); +void *get_efi_config_table(efi_system_table_t *sys_table, efi_guid_t guid); + /* Helper macros for the usual case of using simple C variables: */ #ifndef fdt_setprop_inplace_var #define fdt_setprop_inplace_var(fdt, node_offset, name, var) \ diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index 5440ba17a1c5..0bf0190917e0 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -363,26 +363,17 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size) { - efi_guid_t fdt_guid = DEVICE_TREE_GUID; - efi_config_table_t *tables; - int i; + void *fdt; - tables = (efi_config_table_t *)sys_table->tables; + fdt = get_efi_config_table(sys_table, DEVICE_TREE_GUID); - for (i = 0; i < sys_table->nr_tables; i++) { - void *fdt; + if (!fdt) + return NULL; - if (efi_guidcmp(tables[i].guid, fdt_guid) != 0) - continue; - - fdt = (void *)tables[i].table; - if (fdt_check_header(fdt) != 0) { - pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n"); - return NULL; - } - *fdt_size = fdt_totalsize(fdt); - return fdt; + if (fdt_check_header(fdt) != 0) { + pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n"); + return NULL; } - - return NULL; + *fdt_size = fdt_totalsize(fdt); + return fdt; } diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c index 6b3b507a54eb..6c900ba38ab1 100644 --- a/drivers/firmware/efi/libstub/tpm.c +++ b/drivers/firmware/efi/libstub/tpm.c @@ -64,11 +64,13 @@ void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg) 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; unsigned long first_entry_addr, last_entry_addr; size_t log_size, last_entry_size; efi_bool_t truncated; int version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2; void *tcg2_protocol = NULL; + int final_events_size = 0; status = efi_call_early(locate_protocol, &tcg2_guid, NULL, &tcg2_protocol); @@ -134,8 +136,36 @@ void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg) return; } + /* + * 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(sys_table_arg, + LINUX_EFI_TPM_FINAL_LOG_GUID); + if (final_events_table && final_events_table->nr_events) { + struct tcg_pcr_event2_head *header; + int offset; + void *data; + int event_size; + int i = final_events_table->nr_events; + + data = (void *)final_events_table; + offset = sizeof(final_events_table->version) + + sizeof(final_events_table->nr_events); + + while (i) { + header = data + offset + final_events_size; + event_size = __calc_tpm2_event_size(header, + (void *)(long)log_location, + false); + final_events_size += event_size; + i--; + } + } + memset(log_tbl, 0, sizeof(*log_tbl) + log_size); log_tbl->size = log_size; + log_tbl->final_events_preboot_size = final_events_size; log_tbl->version = version; memcpy(log_tbl->log, (void *) first_entry_addr, log_size); diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c index 2c912ea08166..0bdceb5913aa 100644 --- a/drivers/firmware/efi/tpm.c +++ b/drivers/firmware/efi/tpm.c @@ -76,7 +76,7 @@ int __init efi_tpm_eventlog_init(void) goto out; } - tbl_size = tpm2_calc_event_log_size(efi.tpm_final_log + tbl_size = tpm2_calc_event_log_size((void *)efi.tpm_final_log + sizeof(final_tbl->version) + sizeof(final_tbl->nr_events), final_tbl->nr_events, diff --git a/include/linux/efi.h b/include/linux/efi.h index e33c70a52a9d..2a26004a9bdb 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1703,6 +1703,7 @@ struct linux_efi_random_seed { struct linux_efi_tpm_eventlog { u32 size; + u32 final_events_preboot_size; u8 version; u8 log[]; };