Merge tag 'efi-2022-01-rc4-2' of https://source.denx.de/u-boot/custodians/u-boot-efi

Pull request efi-2022-01-rc4-2

UEFI:

* correctly handle missing TPM device
* prepare for block devices for U-Boot as EFI app

# gpg: Signature made Fri 10 Dec 2021 04:29:20 AM EST
# gpg:                using RSA key 6DC4F9C71F29A6FA06B76D33C481DBBC2C051AC4
# gpg: Good signature from "Heinrich Schuchardt <xypron.glpk@gmx.de>" [unknown]
# gpg:                 aka "[jpeg image of size 1389]" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 6DC4 F9C7 1F29 A6FA 06B7  6D33 C481 DBBC 2C05 1AC4

5 files changed, 89 insertions, 26 deletions

diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index 700dc838dd..24f9a2bb75 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -308,6 +308,8 @@ config EFI_TCG2_PROTOCOL
 	bool "EFI_TCG2_PROTOCOL support"
 	default y
 	depends on TPM_V2
+	# Sandbox TPM currently fails on GetCapabilities needed for TCG2
+	depends on !SANDBOX
 	select SHA1
 	select SHA256
 	select SHA384
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 8492b732f3..20b69699fe 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -3016,9 +3016,12 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
 	if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) {
 		if (image_obj->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION) {
 			ret = efi_tcg2_measure_efi_app_invocation(image_obj);
-			if (ret != EFI_SUCCESS) {
-				log_warning("tcg2 measurement fails(0x%lx)\n",
-					    ret);
+			if (ret == EFI_SECURITY_VIOLATION) {
+				/*
+				 * TCG2 Protocol is installed but no TPM device found,
+				 * this is not expected.
+				 */
+				return EFI_EXIT(EFI_SECURITY_VIOLATION);
 			}
 		}
 	}
diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
index eb95580538..773bd0677c 100644
--- a/lib/efi_loader/efi_image_loader.c
+++ b/lib/efi_loader/efi_image_loader.c
@@ -934,9 +934,16 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle,
 
 #if CONFIG_IS_ENABLED(EFI_TCG2_PROTOCOL)
 	/* Measure an PE/COFF image */
-	if (tcg2_measure_pe_image(efi, efi_size, handle,
-				  loaded_image_info))
-		log_err("PE image measurement failed\n");
+	ret = tcg2_measure_pe_image(efi, efi_size, handle, loaded_image_info);
+	if (ret == EFI_SECURITY_VIOLATION) {
+		/*
+		 * TCG2 Protocol is installed but no TPM device found,
+		 * this is not expected.
+		 */
+		log_err("PE image measurement failed, no tpm device found\n");
+		goto err;
+	}
+
 #endif
 
 	/* Copy PE headers */
diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
index 1aba71cd96..49172e3579 100644
--- a/lib/efi_loader/efi_setup.c
+++ b/lib/efi_loader/efi_setup.c
@@ -241,6 +241,10 @@ efi_status_t efi_init_obj_list(void)
 		ret = efi_tcg2_register();
 		if (ret != EFI_SUCCESS)
 			goto out;
+
+		ret = efi_tcg2_do_initial_measurement();
+		if (ret == EFI_SECURITY_VIOLATION)
+			goto out;
 	}
 
 	/* Secure boot */
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index 5f71b188a0..0ae07ef083 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -153,6 +153,15 @@ static u16 alg_to_len(u16 hash_alg)
 	return 0;
 }
 
+static bool is_tcg2_protocol_installed(void)
+{
+	struct efi_handler *handler;
+	efi_status_t ret;
+
+	ret = efi_search_protocol(efi_root, &efi_guid_tcg2_protocol, &handler);
+	return ret == EFI_SUCCESS;
+}
+
 static u32 tcg_event_final_size(struct tpml_digest_values *digest_list)
 {
 	u32 len;
@@ -963,9 +972,12 @@ efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size,
 	IMAGE_NT_HEADERS32 *nt;
 	struct efi_handler *handler;
 
+	if (!is_tcg2_protocol_installed())
+		return EFI_SUCCESS;
+
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS)
-		return ret;
+		return EFI_SECURITY_VIOLATION;
 
 	switch (handle->image_type) {
 	case IMAGE_SUBSYSTEM_EFI_APPLICATION:
@@ -1664,6 +1676,14 @@ void tcg2_uninit(void)
 	event_log.buffer = NULL;
 	efi_free_pool(event_log.final_buffer);
 	event_log.final_buffer = NULL;
+
+	if (!is_tcg2_protocol_installed())
+		return;
+
+	ret = efi_remove_protocol(efi_root, &efi_guid_tcg2_protocol,
+				  (void *)&efi_tcg2_protocol);
+	if (ret != EFI_SUCCESS)
+		log_err("Failed to remove EFI TCG2 protocol\n");
 }
 
 /**
@@ -2172,12 +2192,15 @@ efi_status_t efi_tcg2_measure_efi_app_invocation(struct efi_loaded_image_obj *ha
 	u32 event = 0;
 	struct smbios_entry *entry;
 
+	if (!is_tcg2_protocol_installed())
+		return EFI_SUCCESS;
+
 	if (tcg2_efi_app_invoked)
 		return EFI_SUCCESS;
 
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS)
-		return ret;
+		return EFI_SECURITY_VIOLATION;
 
 	ret = tcg2_measure_boot_variable(dev);
 	if (ret != EFI_SUCCESS)
@@ -2222,6 +2245,9 @@ efi_status_t efi_tcg2_measure_efi_app_exit(void)
 	efi_status_t ret;
 	struct udevice *dev;
 
+	if (!is_tcg2_protocol_installed())
+		return EFI_SUCCESS;
+
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS)
 		return ret;
@@ -2247,6 +2273,12 @@ efi_tcg2_notify_exit_boot_services(struct efi_event *event, void *context)
 	EFI_ENTRY("%p, %p", event, context);
 
 	event_log.ebs_called = true;
+
+	if (!is_tcg2_protocol_installed()) {
+		ret = EFI_SUCCESS;
+		goto out;
+	}
+
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS)
 		goto out;
@@ -2276,6 +2308,9 @@ efi_status_t efi_tcg2_notify_exit_boot_services_failed(void)
 	struct udevice *dev;
 	efi_status_t ret;
 
+	if (!is_tcg2_protocol_installed())
+		return EFI_SUCCESS;
+
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS)
 		goto out;
@@ -2346,11 +2381,36 @@ error:
 }
 
 /**
+ * efi_tcg2_do_initial_measurement() - do initial measurement
+ *
+ * Return:	status code
+ */
+efi_status_t efi_tcg2_do_initial_measurement(void)
+{
+	efi_status_t ret;
+	struct udevice *dev;
+
+	if (!is_tcg2_protocol_installed())
+		return EFI_SUCCESS;
+
+	ret = platform_get_tpm2_device(&dev);
+	if (ret != EFI_SUCCESS)
+		return EFI_SECURITY_VIOLATION;
+
+	ret = tcg2_measure_secure_boot_variable(dev);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+out:
+	return ret;
+}
+
+/**
  * efi_tcg2_register() - register EFI_TCG2_PROTOCOL
  *
  * If a TPM2 device is available, the TPM TCG2 Protocol is registered
  *
- * Return:	An error status is only returned if adding the protocol fails.
+ * Return:	status code
  */
 efi_status_t efi_tcg2_register(void)
 {
@@ -2373,8 +2433,10 @@ efi_status_t efi_tcg2_register(void)
 	}
 
 	ret = efi_init_event_log();
-	if (ret != EFI_SUCCESS)
+	if (ret != EFI_SUCCESS) {
+		tcg2_uninit();
 		goto fail;
+	}
 
 	ret = efi_add_protocol(efi_root, &efi_guid_tcg2_protocol,
 			       (void *)&efi_tcg2_protocol);
@@ -2391,24 +2453,9 @@ efi_status_t efi_tcg2_register(void)
 		goto fail;
 	}
 
-	ret = tcg2_measure_secure_boot_variable(dev);
-	if (ret != EFI_SUCCESS) {
-		tcg2_uninit();
-		goto fail;
-	}
-
 	return ret;
 
 fail:
 	log_err("Cannot install EFI_TCG2_PROTOCOL\n");
-	/*
-	 * Return EFI_SUCCESS and don't stop the EFI subsystem.
-	 * That's done for 2 reasons
-	 * - If the protocol is not installed the PCRs won't be extended.  So
-	 *   someone later in the boot flow will notice that and take the
-	 *   necessary actions.
-	 * - The TPM sandbox is limited and we won't be able to run any efi
-	 *   related tests with TCG2 enabled
-	 */
-	return EFI_SUCCESS;
+	return ret;
 }