diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 708d356..20b1fe3 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -328,6 +328,42 @@ unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 }
 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 
+static bool tpm_validate_command(struct tpm_chip *chip, const u8 *cmd,
+				 size_t len)
+{
+	const struct tpm_input_header *header = (const void *)cmd;
+	int i;
+	u32 cc;
+	u32 attrs;
+	unsigned int nr_handles;
+
+	if (len < TPM_HEADER_SIZE)
+		return false;
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
+		cc = be32_to_cpu(header->ordinal);
+
+		i = tpm2_find_cc(chip, cc);
+		if (i < 0) {
+			dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
+				cc);
+			return false;
+		}
+
+		attrs = chip->cc_attrs_tbl[i];
+		nr_handles =
+			4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
+		if (len < TPM_HEADER_SIZE + 4 * nr_handles)
+			goto err_len;
+	}
+
+	return true;
+err_len:
+	dev_dbg(&chip->dev,
+		"%s: insufficient command length %zu", __func__, len);
+	return false;
+}
+
 /**
  * tmp_transmit - Internal kernel interface to transmit TPM commands.
  *
@@ -348,7 +384,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 	u32 count, ordinal;
 	unsigned long stop;
 
-	if (bufsiz < TPM_HEADER_SIZE)
+	if (!tpm_validate_command(chip, buf, bufsiz))
 		return -EINVAL;
 
 	if (bufsiz > TPM_BUFSIZE)
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 4937b56..8568dda 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -114,6 +114,7 @@ enum tpm2_command_codes {
 	TPM2_CC_CREATE		= 0x0153,
 	TPM2_CC_LOAD		= 0x0157,
 	TPM2_CC_UNSEAL		= 0x015E,
+	TPM2_CC_CONTEXT_SAVE	= 0x0162,
 	TPM2_CC_FLUSH_CONTEXT	= 0x0165,
 	TPM2_CC_GET_CAPABILITY	= 0x017A,
 	TPM2_CC_GET_RANDOM	= 0x017B,
@@ -127,15 +128,25 @@ enum tpm2_permanent_handles {
 };
 
 enum tpm2_capabilities {
+	TPM2_CAP_COMMANDS	= 2,
 	TPM2_CAP_PCRS		= 5,
 	TPM2_CAP_TPM_PROPERTIES = 6,
 };
 
+enum tpm2_properties {
+	TPM_PT_TOTAL_COMMANDS	= 0x0129,
+};
+
 enum tpm2_startup_types {
 	TPM2_SU_CLEAR	= 0x0000,
 	TPM2_SU_STATE	= 0x0001,
 };
 
+enum tpm2_cc_attrs {
+	TPM2_CC_ATTR_CHANDLES	= 25,
+	TPM2_CC_ATTR_RHANDLE	= 28,
+};
+
 #define TPM_VID_INTEL    0x8086
 #define TPM_VID_WINBOND  0x1050
 #define TPM_VID_STM      0x104A
@@ -199,6 +210,9 @@ struct tpm_chip {
 	acpi_handle acpi_dev_handle;
 	char ppi_version[TPM_PPI_VERSION_LEN + 1];
 #endif /* CONFIG_ACPI */
+
+	u32 nr_commands;
+	u32 *cc_attrs_tbl;
 };
 
 #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
@@ -554,4 +568,5 @@ int tpm2_auto_startup(struct tpm_chip *chip);
 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type);
 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);
 int tpm2_probe(struct tpm_chip *chip);
+int tpm2_find_cc(struct tpm_chip *chip, u32 cc);
 #endif
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 881aea9..5efe9c4 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -1067,15 +1067,76 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
 	return rc;
 }
 
+static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
+{
+	struct tpm_buf buf;
+	u32 nr_commands;
+	u32 *attrs;
+	u32 cc;
+	int i;
+	int rc;
+
+	rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL);
+	if (rc)
+		goto out;
+
+	if (nr_commands > 0xFFFFF) {
+		rc = -EFAULT;
+		goto out;
+	}
+
+	chip->cc_attrs_tbl = devm_kzalloc(&chip->dev, 4 * nr_commands,
+					  GFP_KERNEL);
+
+	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
+	if (rc)
+		goto out;
+
+	tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS);
+	tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
+	tpm_buf_append_u32(&buf, nr_commands);
+
+	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 9 + 4 * nr_commands,
+			      0, NULL);
+	if (rc) {
+		tpm_buf_destroy(&buf);
+		goto out;
+	}
+
+	if (nr_commands !=
+	    be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
+		tpm_buf_destroy(&buf);
+		goto out;
+	}
+
+	chip->nr_commands = nr_commands;
+
+	attrs = (u32 *)&buf.data[TPM_HEADER_SIZE + 9];
+	for (i = 0; i < nr_commands; i++, attrs++) {
+		chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
+		cc = chip->cc_attrs_tbl[i] & 0xFFFF;
+
+		if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) {
+			chip->cc_attrs_tbl[i] &=
+				~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES);
+			chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES;
+		}
+	}
+
+	tpm_buf_destroy(&buf);
+
+out:
+	if (rc > 0)
+		rc = -ENODEV;
+	return rc;
+}
+
 /**
  * tpm2_auto_startup - Perform the standard automatic TPM initialization
  *                     sequence
  * @chip: TPM chip to use
  *
- * Initializes timeout values for operation and command durations, conducts
- * a self-test and reads the list of active PCR banks.
- *
- * Return: 0 on success. Otherwise, a system error code is returned.
+ * Returns 0 on success, < 0 in case of fatal error.
  */
 int tpm2_auto_startup(struct tpm_chip *chip)
 {
@@ -1104,9 +1165,24 @@ int tpm2_auto_startup(struct tpm_chip *chip)
 	}
 
 	rc = tpm2_get_pcr_allocation(chip);
+	if (rc)
+		goto out;
+
+	rc = tpm2_get_cc_attrs_tbl(chip);
 
 out:
 	if (rc > 0)
 		rc = -ENODEV;
 	return rc;
 }
+
+int tpm2_find_cc(struct tpm_chip *chip, u32 cc)
+{
+	int i;
+
+	for (i = 0; i < chip->nr_commands; i++)
+		if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0)))
+			return i;
+
+	return -1;
+}
