4 files changed, 57 insertions, 9 deletions

diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c
index 3633ed70f48f..1b18ce5ebab1 100644
--- a/drivers/char/tpm/eventlog/acpi.c
+++ b/drivers/char/tpm/eventlog/acpi.c
@@ -41,6 +41,27 @@ struct acpi_tcpa {
 	};
 };
 
+/* Check that the given log is indeed a TPM2 log. */
+static bool tpm_is_tpm2_log(void *bios_event_log, u64 len)
+{
+	struct tcg_efi_specid_event_head *efispecid;
+	struct tcg_pcr_event *event_header;
+	int n;
+
+	if (len < sizeof(*event_header))
+		return false;
+	len -= sizeof(*event_header);
+	event_header = bios_event_log;
+
+	if (len < sizeof(*efispecid))
+		return false;
+	efispecid = (struct tcg_efi_specid_event_head *)event_header->event;
+
+	n = memcmp(efispecid->signature, TCG_SPECID_SIG,
+		   sizeof(TCG_SPECID_SIG));
+	return n == 0;
+}
+
 /* read binary bios log */
 int tpm_read_log_acpi(struct tpm_chip *chip)
 {
@@ -52,6 +73,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
 	struct acpi_table_tpm2 *tbl;
 	struct acpi_tpm2_phy *tpm2_phy;
 	int format;
+	int ret;
 
 	log = &chip->log;
 
@@ -112,6 +134,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
 
 	log->bios_event_log_end = log->bios_event_log + len;
 
+	ret = -EIO;
 	virt = acpi_os_map_iomem(start, len);
 	if (!virt)
 		goto err;
@@ -119,11 +142,19 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
 	memcpy_fromio(log->bios_event_log, virt, len);
 
 	acpi_os_unmap_iomem(virt, len);
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2 &&
+	    !tpm_is_tpm2_log(log->bios_event_log, len)) {
+		/* try EFI log next */
+		ret = -ENODEV;
+		goto err;
+	}
+
 	return format;
 
 err:
 	kfree(log->bios_event_log);
 	log->bios_event_log = NULL;
-	return -EIO;
+	return ret;
 
 }
diff --git a/drivers/char/tpm/eventlog/common.c b/drivers/char/tpm/eventlog/common.c
index 7460f230bae4..8512ec76d526 100644
--- a/drivers/char/tpm/eventlog/common.c
+++ b/drivers/char/tpm/eventlog/common.c
@@ -107,6 +107,9 @@ void tpm_bios_log_setup(struct tpm_chip *chip)
 	int log_version;
 	int rc = 0;
 
+	if (chip->flags & TPM_CHIP_FLAG_VIRTUAL)
+		return;
+
 	rc = tpm_read_log(chip);
 	if (rc < 0)
 		return;
diff --git a/drivers/char/tpm/eventlog/efi.c b/drivers/char/tpm/eventlog/efi.c
index 35229e5143ca..e6cb9d525e30 100644
--- a/drivers/char/tpm/eventlog/efi.c
+++ b/drivers/char/tpm/eventlog/efi.c
@@ -17,6 +17,7 @@ int tpm_read_log_efi(struct tpm_chip *chip)
 {
 
 	struct efi_tcg2_final_events_table *final_tbl = NULL;
+	int final_events_log_size = efi_tpm_final_log_size;
 	struct linux_efi_tpm_eventlog *log_tbl;
 	struct tpm_bios_log *log;
 	u32 log_size;
@@ -66,12 +67,12 @@ int tpm_read_log_efi(struct tpm_chip *chip)
 	ret = tpm_log_version;
 
 	if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR ||
-	    efi_tpm_final_log_size == 0 ||
+	    final_events_log_size == 0 ||
 	    tpm_log_version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2)
 		goto out;
 
 	final_tbl = memremap(efi.tpm_final_log,
-			     sizeof(*final_tbl) + efi_tpm_final_log_size,
+			     sizeof(*final_tbl) + final_events_log_size,
 			     MEMREMAP_WB);
 	if (!final_tbl) {
 		pr_err("Could not map UEFI TPM final log\n");
@@ -80,10 +81,18 @@ int tpm_read_log_efi(struct tpm_chip *chip)
 		goto out;
 	}
 
-	efi_tpm_final_log_size -= log_tbl->final_events_preboot_size;
+	/*
+	 * The 'final events log' size excludes the 'final events preboot log'
+	 * at its beginning.
+	 */
+	final_events_log_size -= log_tbl->final_events_preboot_size;
 
+	/*
+	 * Allocate memory for the 'combined log' where we will append the
+	 * 'final events log' to.
+	 */
 	tmp = krealloc(log->bios_event_log,
-		       log_size + efi_tpm_final_log_size,
+		       log_size + final_events_log_size,
 		       GFP_KERNEL);
 	if (!tmp) {
 		kfree(log->bios_event_log);
@@ -94,15 +103,19 @@ 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
+	 * Append 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 + log_tbl->final_events_preboot_size,
-	       efi_tpm_final_log_size);
+	       final_events_log_size);
+	/*
+	 * The size of the 'combined log' is the size of the 'main log' plus
+	 * the size of the 'final events log'.
+	 */
 	log->bios_event_log_end = log->bios_event_log +
-		log_size + efi_tpm_final_log_size;
+		log_size + final_events_log_size;
 
 out:
 	memunmap(final_tbl);
diff --git a/drivers/char/tpm/tpm_tis_i2c_cr50.c b/drivers/char/tpm/tpm_tis_i2c_cr50.c
index ec9a65e7887d..f19c227d20f4 100644
--- a/drivers/char/tpm/tpm_tis_i2c_cr50.c
+++ b/drivers/char/tpm/tpm_tis_i2c_cr50.c
@@ -483,6 +483,7 @@ static int tpm_cr50_i2c_tis_recv(struct tpm_chip *chip, u8 *buf, size_t buf_len)
 	expected = be32_to_cpup((__be32 *)(buf + 2));
 	if (expected > buf_len) {
 		dev_err(&chip->dev, "Buffer too small to receive i2c data\n");
+		rc = -E2BIG;
 		goto out_err;
 	}