diff options
author | Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> | 2016-08-16 22:00:38 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-10-16 17:50:39 +0200 |
commit | b7bab5ad129477c430f3c138fd597e14916961a6 (patch) | |
tree | 886bf0315f78b9be17c6a126531dbbbc33418634 | |
parent | 889995959eb082d515effe001e51bbf2f7324059 (diff) | |
download | lwn-b7bab5ad129477c430f3c138fd597e14916961a6.tar.gz lwn-b7bab5ad129477c430f3c138fd597e14916961a6.zip |
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: 0fe5480303a1 ("keys, trusted: seal/unseal with TPM 2.0 chips")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/char/tpm/tpm-dev.c | 2 | ||||
-rw-r--r-- | drivers/char/tpm/tpm-interface.c | 51 | ||||
-rw-r--r-- | drivers/char/tpm/tpm-sysfs.c | 2 | ||||
-rw-r--r-- | drivers/char/tpm/tpm.h | 12 | ||||
-rw-r--r-- | drivers/char/tpm/tpm2-cmd.c | 101 |
5 files changed, 103 insertions, 65 deletions
diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c index de0337ebd658..4f3137d9a35e 100644 --- a/drivers/char/tpm/tpm-dev.c +++ b/drivers/char/tpm/tpm-dev.c @@ -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; diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index e2fa89c88304..9ba86eb3f2ef 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -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 @@ out_recv: 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 @@ 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; @@ -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; diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c index ee66fd4673f3..f880856aa75e 100644 --- a/drivers/char/tpm/tpm-sysfs.c +++ b/drivers/char/tpm/tpm-sysfs.c @@ -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; diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 28b477e8da6a..f475b747454b 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -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 *); diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index ca2d2386a4eb..19f14dc4cda7 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -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 @@ out: 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 @@ 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; @@ -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) |