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Commit 5779f6eb authored by Jarkko Sakkinen's avatar Jarkko Sakkinen Committed by Luis Henriques
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tpm: fix a race condition in tpm2_unseal_trusted() 

BugLink: http://bugs.launchpad.net/bugs/1634153

commit d4816edf 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>
Signed-off-by: default avatarTim Gardner <tim.gardner@canonical.com>
Signed-off-by: default avatarSeth Forshee <seth.forshee@canonical.com>
parent edf4c79e
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Showing with 103 additions and 65 deletions
drivers/char/tpm/tpm-dev.c
View file @ 5779f6eb
......@@ -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
View file @ 5779f6eb
......@@ -330,8 +330,8 @@ 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;
......@@ -350,7 +350,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
return -E2BIG;
}
mutex_lock(&chip->tpm_mutex);
if (!(flags & TPM_TRANSMIT_UNLOCKED))
mutex_lock(&chip->tpm_mutex);
rc = chip->ops->send(chip, (u8 *) buf, count);
if (rc < 0) {
......@@ -393,20 +394,21 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
dev_err(chip->pdev,
"tpm_transmit: tpm_recv: error %zd\n", rc);
out:
mutex_unlock(&chip->tpm_mutex);
if (!(flags & TPM_TRANSMIT_UNLOCKED))
mutex_unlock(&chip->tpm_mutex);
return rc;
}
#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)
......@@ -454,7 +456,8 @@ 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;
......@@ -470,7 +473,7 @@ 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);
......@@ -491,7 +494,7 @@ 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");
}
......@@ -522,7 +525,8 @@ 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.
......@@ -536,7 +540,7 @@ 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,
......@@ -597,7 +601,7 @@ 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_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;
......@@ -653,7 +657,7 @@ 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;
}
......@@ -673,7 +677,7 @@ 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)
......@@ -771,7 +775,7 @@ 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);
......@@ -810,7 +814,7 @@ 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. */
......@@ -851,7 +855,7 @@ 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;
......@@ -953,14 +957,15 @@ 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
......@@ -1044,8 +1049,8 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
err = tpm_transmit_cmd(chip, &tpm_cmd,
TPM_GETRANDOM_RESULT_SIZE + num_bytes,
"attempting get random");
TPM_GETRANDOM_RESULT_SIZE + num_bytes,
0, "attempting get random");
if (err)
break;
......
drivers/char/tpm/tpm-sysfs.c
View file @ 5779f6eb
......@@ -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
View file @ 5779f6eb
......@@ -494,11 +494,15 @@ 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
View file @ 5779f6eb
......@@ -282,7 +282,7 @@ 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;
......@@ -330,7 +330,7 @@ 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;
......@@ -376,7 +376,7 @@ 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;
......@@ -434,12 +434,12 @@ 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,
......@@ -512,7 +512,7 @@ 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;
......@@ -538,10 +538,18 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
return rc;
}
static int tpm2_load(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options,
u32 *blob_handle)
/**
* 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, unsigned int flags)
{
struct tpm_buf buf;
unsigned int private_len;
......@@ -576,7 +584,7 @@ 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]);
......@@ -590,7 +598,16 @@ static int tpm2_load(struct tpm_chip *chip,
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;
......@@ -604,7 +621,8 @@ 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);
......@@ -612,10 +630,18 @@ static void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
tpm_buf_destroy(&buf);
}
static int tpm2_unseal(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options,
u32 blob_handle)
/**
* 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, unsigned int flags)
{
struct tpm_buf buf;
u16 data_len;
......@@ -635,7 +661,7 @@ 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;
......@@ -654,12 +680,12 @@ 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,
......@@ -668,14 +694,17 @@ 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;
}
......@@ -701,7 +730,7 @@ 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);
......@@ -735,7 +764,7 @@ 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);
......@@ -764,7 +793,7 @@ 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.
......@@ -830,7 +859,7 @@ 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
......@@ -882,7 +911,7 @@ 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;
......@@ -931,7 +960,7 @@ 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)
......
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