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Commit c0201ae6 authored by Jarkko Sakkinen's avatar Jarkko Sakkinen Committed by Greg Kroah-Hartman
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tpm: fix a race condition in tpm2_unseal_trusted() 



commit d4816edfe706497a8525480c1685ceb9871bc118 upstream.

Unseal and load operations should be done as an atomic operation. This
commit introduces unlocked tpm_transmit() so that tpm2_unseal_trusted()
can do the locking by itself.

Fixes: 0fe54803 ("keys, trusted: seal/unseal with TPM 2.0 chips")
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: default avatarJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0040b746

drivers/char/tpm/tpm-dev.c

+1 −1
Original line number Diff line number Diff line
@@ -139,7 +139,7 @@ static ssize_t tpm_write(struct file *file, const char __user *buf, 


	/* atomic tpm command send and result receive */

	out_size = tpm_transmit(priv->chip, priv->data_buffer,

				sizeof(priv->data_buffer));

				sizeof(priv->data_buffer), 0);

	if (out_size < 0) {

		mutex_unlock(&priv->buffer_mutex);

		return out_size;

drivers/char/tpm/tpm-interface.c

+28 −23
Original line number Diff line number Diff line
@@ -328,8 +328,8 @@ EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration); 
/*

 * Internal kernel interface to transmit TPM commands

 */

ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,

		     size_t bufsiz)

ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,

		     unsigned int flags)

{

	ssize_t rc;

	u32 count, ordinal;
@@ -348,6 +348,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, 
		return -E2BIG;

	}



	if (!(flags & TPM_TRANSMIT_UNLOCKED))

		mutex_lock(&chip->tpm_mutex);



	rc = chip->ops->send(chip, (u8 *) buf, count);
@@ -391,6 +392,7 @@ out_recv: 
		dev_err(chip->pdev,

			"tpm_transmit: tpm_recv: error %zd\n", rc);

out:

	if (!(flags & TPM_TRANSMIT_UNLOCKED))

		mutex_unlock(&chip->tpm_mutex);

	return rc;

}
@@ -398,13 +400,13 @@ out: 
#define TPM_DIGEST_SIZE 20

#define TPM_RET_CODE_IDX 6



ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd,

			 int len, const char *desc)

ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,

			 int len, unsigned int flags, const char *desc)

{

	struct tpm_output_header *header;

	const struct tpm_output_header *header;

	int err;



	len = tpm_transmit(chip, (u8 *) cmd, len);

	len = tpm_transmit(chip, (const u8 *)cmd, len, flags);

	if (len <  0)

		return len;

	else if (len < TPM_HEADER_SIZE)
@@ -452,7 +454,8 @@ ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap, 
		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);

		tpm_cmd.params.getcap_in.subcap = subcap_id;

	}

	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);

	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,

			      desc);

	if (!rc)

		*cap = tpm_cmd.params.getcap_out.cap;

	return rc;
@@ -468,7 +471,7 @@ void tpm_gen_interrupt(struct tpm_chip *chip) 
	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);

	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;



	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,

	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,

			      "attempting to determine the timeouts");

}

EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
@@ -489,7 +492,7 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type) 
	start_cmd.header.in = tpm_startup_header;



	start_cmd.params.startup_in.startup_type = startup_type;

	return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,

	return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,

				"attempting to start the TPM");

}
@@ -505,7 +508,8 @@ int tpm_get_timeouts(struct tpm_chip *chip) 
	tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;

	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);

	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;

	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);

	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,

			      NULL);



	if (rc == TPM_ERR_INVALID_POSTINIT) {

		/* The TPM is not started, we are the first to talk to it.
@@ -519,7 +523,7 @@ int tpm_get_timeouts(struct tpm_chip *chip) 
		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);

		tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;

		rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,

				  NULL);

				      0, NULL);

	}

	if (rc) {

		dev_err(chip->pdev,
@@ -580,7 +584,7 @@ duration: 
	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);

	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;



	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,

	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,

			      "attempting to determine the durations");

	if (rc)

		return rc;
@@ -636,7 +640,7 @@ static int tpm_continue_selftest(struct tpm_chip *chip) 
	struct tpm_cmd_t cmd;



	cmd.header.in = continue_selftest_header;

	rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,

	rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,

			      "continue selftest");

	return rc;

}
@@ -656,7 +660,7 @@ int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) 


	cmd.header.in = pcrread_header;

	cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);

	rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,

	rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,

			      "attempting to read a pcr value");



	if (rc == 0)
@@ -754,7 +758,7 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) 
	cmd.header.in = pcrextend_header;

	cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);

	memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);

	rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,

	rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,

			      "attempting extend a PCR value");



	tpm_chip_put(chip);
@@ -793,7 +797,7 @@ int tpm_do_selftest(struct tpm_chip *chip) 
		/* Attempt to read a PCR value */

		cmd.header.in = pcrread_header;

		cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);

		rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);

		rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE, 0);

		/* Some buggy TPMs will not respond to tpm_tis_ready() for

		 * around 300ms while the self test is ongoing, keep trying

		 * until the self test duration expires. */
@@ -834,7 +838,7 @@ int tpm_send(u32 chip_num, void *cmd, size_t buflen) 
	if (chip == NULL)

		return -ENODEV;



	rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");

	rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");



	tpm_chip_put(chip);

	return rc;
@@ -936,14 +940,15 @@ int tpm_pm_suspend(struct device *dev) 
		cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);

		memcpy(cmd.params.pcrextend_in.hash, dummy_hash,

		       TPM_DIGEST_SIZE);

		rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,

		rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,

				      "extending dummy pcr before suspend");

	}



	/* now do the actual savestate */

	for (try = 0; try < TPM_RETRY; try++) {

		cmd.header.in = savestate_header;

		rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);

		rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,

				      NULL);



		/*

		 * If the TPM indicates that it is too busy to respond to
@@ -1028,7 +1033,7 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) 


		err = tpm_transmit_cmd(chip, &tpm_cmd,

				       TPM_GETRANDOM_RESULT_SIZE + num_bytes,

				   "attempting get random");

				       0, "attempting get random");

		if (err)

			break;

drivers/char/tpm/tpm-sysfs.c

+1 −1
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr, 
	struct tpm_chip *chip = dev_get_drvdata(dev);



	tpm_cmd.header.in = tpm_readpubek_header;

	err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,

	err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE, 0,

			       "attempting to read the PUBEK");

	if (err)

		goto out;

drivers/char/tpm/tpm.h

+8 −4
Original line number Diff line number Diff line
@@ -498,11 +498,15 @@ extern struct class *tpm_class; 
extern dev_t tpm_devt;

extern const struct file_operations tpm_fops;



enum tpm_transmit_flags {

	TPM_TRANSMIT_UNLOCKED	= BIT(0),

};



ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,

		     unsigned int flags);

ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd, int len,

			 unsigned int flags, const char *desc);

ssize_t	tpm_getcap(struct device *, __be32, cap_t *, const char *);

ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,

		     size_t bufsiz);

ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, int len,

			 const char *desc);

extern int tpm_get_timeouts(struct tpm_chip *);

extern void tpm_gen_interrupt(struct tpm_chip *);

extern int tpm_do_selftest(struct tpm_chip *);

drivers/char/tpm/tpm2-cmd.c

+65 −36
Original line number Diff line number Diff line
@@ -264,7 +264,7 @@ int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) 
	       sizeof(cmd.params.pcrread_in.pcr_select));

	cmd.params.pcrread_in.pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);



	rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),

	rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,

			      "attempting to read a pcr value");

	if (rc == 0) {

		buf = cmd.params.pcrread_out.digest;
@@ -312,7 +312,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash) 
	cmd.params.pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);

	memcpy(cmd.params.pcrextend_in.digest, hash, TPM_DIGEST_SIZE);



	rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),

	rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,

			      "attempting extend a PCR value");



	return rc;
@@ -358,7 +358,7 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max) 
		cmd.header.in = tpm2_getrandom_header;

		cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);



		err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),

		err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,

				       "attempting get random");

		if (err)

			break;
@@ -416,12 +416,12 @@ static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle, 
}



/**

 * tpm2_seal_trusted() - seal a trusted key

 * @chip_num: A specific chip number for the request or TPM_ANY_NUM

 * @options: authentication values and other options

 * tpm2_seal_trusted() - seal the payload of a trusted key

 * @chip_num: TPM chip to use

 * @payload: the key data in clear and encrypted form

 * @options: authentication values and other options

 *

 * Returns < 0 on error and 0 on success.

 * Return: < 0 on error and 0 on success.

 */

int tpm2_seal_trusted(struct tpm_chip *chip,

		      struct trusted_key_payload *payload,
@@ -472,7 +472,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip, 
		goto out;

	}



	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "sealing data");

	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, "sealing data");

	if (rc)

		goto out;
@@ -494,10 +494,18 @@ out: 
	return rc;

}



static int tpm2_load(struct tpm_chip *chip,

/**

 * tpm2_load_cmd() - execute a TPM2_Load command

 * @chip_num: TPM chip to use

 * @payload: the key data in clear and encrypted form

 * @options: authentication values and other options

 *

 * Return: same as with tpm_transmit_cmd

 */

static int tpm2_load_cmd(struct tpm_chip *chip,

			 struct trusted_key_payload *payload,

			 struct trusted_key_options *options,

		     u32 *blob_handle)

			 u32 *blob_handle, unsigned int flags)

{

	struct tpm_buf buf;

	unsigned int private_len;
@@ -532,7 +540,7 @@ static int tpm2_load(struct tpm_chip *chip, 
		goto out;

	}



	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob");

	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags, "loading blob");

	if (!rc)

		*blob_handle = be32_to_cpup(

			(__be32 *) &buf.data[TPM_HEADER_SIZE]);
@@ -546,7 +554,16 @@ out: 
	return rc;

}



static void tpm2_flush_context(struct tpm_chip *chip, u32 handle)

/**

 * tpm2_flush_context_cmd() - execute a TPM2_FlushContext command

 * @chip_num: TPM chip to use

 * @payload: the key data in clear and encrypted form

 * @options: authentication values and other options

 *

 * Return: same as with tpm_transmit_cmd

 */

static void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,

				   unsigned int flags)

{

	struct tpm_buf buf;

	int rc;
@@ -560,7 +577,8 @@ static void tpm2_flush_context(struct tpm_chip *chip, u32 handle) 


	tpm_buf_append_u32(&buf, handle);



	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "flushing context");

	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags,

			      "flushing context");

	if (rc)

		dev_warn(chip->pdev, "0x%08x was not flushed, rc=%d\n", handle,

			 rc);
@@ -568,10 +586,18 @@ static void tpm2_flush_context(struct tpm_chip *chip, u32 handle) 
	tpm_buf_destroy(&buf);

}



static int tpm2_unseal(struct tpm_chip *chip,

/**

 * tpm2_unseal_cmd() - execute a TPM2_Unload command

 * @chip_num: TPM chip to use

 * @payload: the key data in clear and encrypted form

 * @options: authentication values and other options

 *

 * Return: same as with tpm_transmit_cmd

 */

static int tpm2_unseal_cmd(struct tpm_chip *chip,

			   struct trusted_key_payload *payload,

			   struct trusted_key_options *options,

		       u32 blob_handle)

			   u32 blob_handle, unsigned int flags)

{

	struct tpm_buf buf;

	u16 data_len;
@@ -589,7 +615,7 @@ static int tpm2_unseal(struct tpm_chip *chip, 
			     options->blobauth /* hmac */,

			     TPM_DIGEST_SIZE);



	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "unsealing");

	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags, "unsealing");

	if (rc > 0)

		rc = -EPERM;
@@ -608,12 +634,12 @@ static int tpm2_unseal(struct tpm_chip *chip, 
}



/**

 * tpm_unseal_trusted() - unseal a trusted key

 * @chip_num: A specific chip number for the request or TPM_ANY_NUM

 * @options: authentication values and other options

 * tpm_unseal_trusted() - unseal the payload of a trusted key

 * @chip_num: TPM chip to use

 * @payload: the key data in clear and encrypted form

 * @options: authentication values and other options

 *

 * Returns < 0 on error and 0 on success.

 * Return: < 0 on error and 0 on success.

 */

int tpm2_unseal_trusted(struct tpm_chip *chip,

			struct trusted_key_payload *payload,
@@ -622,14 +648,17 @@ int tpm2_unseal_trusted(struct tpm_chip *chip, 
	u32 blob_handle;

	int rc;



	rc = tpm2_load(chip, payload, options, &blob_handle);

	mutex_lock(&chip->tpm_mutex);

	rc = tpm2_load_cmd(chip, payload, options, &blob_handle,

			   TPM_TRANSMIT_UNLOCKED);

	if (rc)

		return rc;



	rc = tpm2_unseal(chip, payload, options, blob_handle);



	tpm2_flush_context(chip, blob_handle);

		goto out;



	rc = tpm2_unseal_cmd(chip, payload, options, blob_handle,

			     TPM_TRANSMIT_UNLOCKED);

	tpm2_flush_context_cmd(chip, blob_handle, TPM_TRANSMIT_UNLOCKED);

out:

	mutex_unlock(&chip->tpm_mutex);

	return rc;

}
@@ -655,7 +684,7 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value, 
	cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);

	cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);



	rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), desc);

	rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, desc);

	if (!rc)

		*value = be32_to_cpu(cmd.params.get_tpm_pt_out.value);
@@ -689,7 +718,7 @@ int tpm2_startup(struct tpm_chip *chip, u16 startup_type) 
	cmd.header.in = tpm2_startup_header;



	cmd.params.startup_in.startup_type = cpu_to_be16(startup_type);

	return tpm_transmit_cmd(chip, &cmd, sizeof(cmd),

	return tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,

				"attempting to start the TPM");

}

EXPORT_SYMBOL_GPL(tpm2_startup);
@@ -718,7 +747,7 @@ void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type) 
	cmd.header.in = tpm2_shutdown_header;

	cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);



	rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), "stopping the TPM");

	rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, "stopping the TPM");



	/* In places where shutdown command is sent there's no much we can do

	 * except print the error code on a system failure.
@@ -784,7 +813,7 @@ static int tpm2_start_selftest(struct tpm_chip *chip, bool full) 
	cmd.header.in = tpm2_selftest_header;

	cmd.params.selftest_in.full_test = full;



	rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE,

	rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE, 0,

			      "continue selftest");



	/* At least some prototype chips seem to give RC_TESTING error
@@ -836,7 +865,7 @@ int tpm2_do_selftest(struct tpm_chip *chip) 
		cmd.params.pcrread_in.pcr_select[1] = 0x00;

		cmd.params.pcrread_in.pcr_select[2] = 0x00;



		rc = tpm_transmit_cmd(chip, (u8 *) &cmd, sizeof(cmd), NULL);

		rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, NULL);

		if (rc < 0)

			break;
@@ -885,7 +914,7 @@ int tpm2_probe(struct tpm_chip *chip) 
	cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);

	cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);



	rc = tpm_transmit(chip, (const char *) &cmd, sizeof(cmd));

	rc = tpm_transmit(chip, (const u8 *)&cmd, sizeof(cmd), 0);

	if (rc <  0)

		return rc;

	else if (rc < TPM_HEADER_SIZE)