When tpm_get_random() was introduced, it defined the following API for the return value:
1. A positive value tells how many bytes of random data was generated. 2. A negative value on error.
However, in the call sites the API was used incorrectly, i.e. as it would only return negative values and otherwise zero. Returning he positive read counts to the user space does not make any possible sense.
Fix this by returning -EIO when tpm_get_random() returns a positive value.
Fixes: 41ab999c80f1 ("tpm: Move tpm_get_random api into the TPM device driver") Cc: Kent Yoder key@linux.vnet.ibm.com Cc: David Howells dhowells@redhat.com Cc: "James E.J. Bottomley" James.Bottomley@HansenPartnership.com Cc: stable@vger.kernel.org Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com --- security/keys/trusted-keys/trusted_tpm1.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index b9fe02e5f84f..c7b1701cdac5 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -403,9 +403,12 @@ static int osap(struct tpm_buf *tb, struct osapsess *s, int ret;
ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE); - if (ret != TPM_NONCE_SIZE) + if (ret < 0) return ret;
+ if (ret != TPM_NONCE_SIZE) + return -EIO; + tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP); tpm_buf_append_u16(tb, type); tpm_buf_append_u32(tb, handle); @@ -496,8 +499,12 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, goto out;
ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE); + if (ret < 0) + return ret; + if (ret != TPM_NONCE_SIZE) - goto out; + return -EIO; + ordinal = htonl(TPM_ORD_SEAL); datsize = htonl(datalen); pcrsize = htonl(pcrinfosize); @@ -601,9 +608,12 @@ static int tpm_unseal(struct tpm_buf *tb,
ordinal = htonl(TPM_ORD_UNSEAL); ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE); + if (ret < 0) + return ret; + if (ret != TPM_NONCE_SIZE) { pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); - return ret; + return -EIO; } ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE, enonce1, nonceodd, cont, sizeof(uint32_t), @@ -1013,8 +1023,12 @@ static int trusted_instantiate(struct key *key, case Opt_new: key_len = payload->key_len; ret = tpm_get_random(chip, payload->key, key_len); + if (ret < 0) + goto out; + if (ret != key_len) { pr_info("trusted_key: key_create failed (%d)\n", ret); + ret = -EIO; goto out; } if (tpm2)
When TPM 2.0 trusted keys code was moved to the trusted keys subsystem, the operations were unwrapped from tpm_try_get_ops() and tpm_put_ops(), which are used to take temporarily the ownership of the TPM chip. The ownership is only taken inside tpm_send(), but this is not sufficient, as in the key load TPM2_CC_LOAD, TPM2_CC_UNSEAL and TPM2_FLUSH_CONTEXT need to be done as a one single atom.
Fix this issue by introducting trusted_tpm_load() and trusted_tpm_new(), which wrap these operations, and take the TPM chip ownership before sending anything. Use tpm_transmit_cmd() to send TPM commands instead of tpm_send(), reverting back to the old behaviour.
Fixes: 2e19e10131a0 ("KEYS: trusted: Move TPM2 trusted keys code") Reported-by: "James E.J. Bottomley" James.Bottomley@HansenPartnership.com Cc: Sumit Garg sumit.garg@linaro.org Cc: David Howells dhowells@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com --- drivers/char/tpm/tpm.h | 4 -- include/linux/tpm.h | 16 ++++- security/keys/trusted-keys/trusted_tpm1.c | 78 +++++++++++++++-------- security/keys/trusted-keys/trusted_tpm2.c | 6 +- 4 files changed, 71 insertions(+), 33 deletions(-)
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 947d1db0a5cc..283f78211c3a 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -164,8 +164,6 @@ extern const struct file_operations tpmrm_fops; extern struct idr dev_nums_idr;
ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz); -ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf, - size_t min_rsp_body_length, const char *desc); int tpm_get_timeouts(struct tpm_chip *); int tpm_auto_startup(struct tpm_chip *chip);
@@ -194,8 +192,6 @@ static inline void tpm_msleep(unsigned int delay_msec) int tpm_chip_start(struct tpm_chip *chip); void tpm_chip_stop(struct tpm_chip *chip); struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip); -__must_check int tpm_try_get_ops(struct tpm_chip *chip); -void tpm_put_ops(struct tpm_chip *chip);
struct tpm_chip *tpm_chip_alloc(struct device *dev, const struct tpm_class_ops *ops); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 8f4ff39f51e7..c908349a2f15 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -397,6 +397,10 @@ static inline u32 tpm2_rc_value(u32 rc) #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)
extern int tpm_is_tpm2(struct tpm_chip *chip); +extern __must_check int tpm_try_get_ops(struct tpm_chip *chip); +extern void tpm_put_ops(struct tpm_chip *chip); +extern ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf, + size_t min_rsp_body_length, const char *desc); extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digest); extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, @@ -410,7 +414,17 @@ static inline int tpm_is_tpm2(struct tpm_chip *chip) { return -ENODEV; } - +static inline int tpm_try_get_ops(struct tpm_chip *chip) +{ + return -ENODEV; +} +static inline void tpm_put_ops(struct tpm_chip *chip) +{ +} +extern ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf, + size_t min_rsp_body_length, const char *desc) +{ +} static inline int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, struct tpm_digest *digest) { diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index c7b1701cdac5..c1dfc32c780b 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -950,6 +950,51 @@ static struct trusted_key_payload *trusted_payload_alloc(struct key *key) return p; }
+static int trusted_tpm_load(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options) +{ + int ret; + + if (tpm_is_tpm2(chip)) { + ret = tpm_try_get_ops(chip); + if (!ret) { + ret = tpm2_unseal_trusted(chip, payload, options); + tpm_put_ops(chip); + } + } else { + ret = key_unseal(payload, options); + } + + return ret; +} + +static int trusted_tpm_new(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options) +{ + int ret; + + ret = tpm_get_random(chip, payload->key, payload->key_len); + if (ret < 0) + return ret; + + if (ret != payload->key_len) + return -EIO; + + if (tpm_is_tpm2(chip)) { + ret = tpm_try_get_ops(chip); + if (!ret) { + ret = tpm2_seal_trusted(chip, payload, options); + tpm_put_ops(chip); + } + } else { + ret = key_seal(payload, options); + } + + return ret; +} + /* * trusted_instantiate - create a new trusted key * @@ -968,12 +1013,6 @@ static int trusted_instantiate(struct key *key, char *datablob; int ret = 0; int key_cmd; - size_t key_len; - int tpm2; - - tpm2 = tpm_is_tpm2(chip); - if (tpm2 < 0) - return tpm2;
if (datalen <= 0 || datalen > 32767 || !prep->data) return -EINVAL; @@ -1011,32 +1050,21 @@ static int trusted_instantiate(struct key *key,
switch (key_cmd) { case Opt_load: - if (tpm2) - ret = tpm2_unseal_trusted(chip, payload, options); - else - ret = key_unseal(payload, options); + ret = trusted_tpm_load(chip, payload, options); + dump_payload(payload); dump_options(options); + if (ret < 0) - pr_info("trusted_key: key_unseal failed (%d)\n", ret); + pr_info("%s: load failed (%d)\n", __func__, ret); + break; case Opt_new: - key_len = payload->key_len; - ret = tpm_get_random(chip, payload->key, key_len); - if (ret < 0) - goto out; + ret = trusted_tpm_new(chip, payload, options);
- if (ret != key_len) { - pr_info("trusted_key: key_create failed (%d)\n", ret); - ret = -EIO; - goto out; - } - if (tpm2) - ret = tpm2_seal_trusted(chip, payload, options); - else - ret = key_seal(payload, options); if (ret < 0) - pr_info("trusted_key: key_seal failed (%d)\n", ret); + pr_info("%s: new failed (%d)\n", __func__, ret); + break; default: ret = -EINVAL; diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 08ec7f48f01d..effdb67fac6d 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -130,7 +130,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip, goto out; }
- rc = tpm_send(chip, buf.data, tpm_buf_length(&buf)); + rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data"); if (rc) goto out;
@@ -211,7 +211,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip, goto out; }
- rc = tpm_send(chip, buf.data, tpm_buf_length(&buf)); + rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob"); if (!rc) *blob_handle = be32_to_cpup( (__be32 *) &buf.data[TPM_HEADER_SIZE]); @@ -260,7 +260,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, options->blobauth /* hmac */, TPM_DIGEST_SIZE);
- rc = tpm_send(chip, buf.data, tpm_buf_length(&buf)); + rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing"); if (rc > 0) rc = -EPERM;
On Wed, Sep 30, 2020 at 01:51:41AM +0300, Jarkko Sakkinen wrote:
When TPM 2.0 trusted keys code was moved to the trusted keys subsystem, the operations were unwrapped from tpm_try_get_ops() and tpm_put_ops(), which are used to take temporarily the ownership of the TPM chip. The ownership is only taken inside tpm_send(), but this is not sufficient, as in the key load TPM2_CC_LOAD, TPM2_CC_UNSEAL and TPM2_FLUSH_CONTEXT need to be done as a one single atom.
Fix this issue by introducting trusted_tpm_load() and trusted_tpm_new(), which wrap these operations, and take the TPM chip ownership before sending anything. Use tpm_transmit_cmd() to send TPM commands instead of tpm_send(), reverting back to the old behaviour.
Fixes: 2e19e10131a0 ("KEYS: trusted: Move TPM2 trusted keys code") Reported-by: "James E.J. Bottomley" James.Bottomley@HansenPartnership.com Cc: Sumit Garg sumit.garg@linaro.org Cc: David Howells dhowells@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com
I double checked that patches were in my BuildRoot rootfs and kernel.
I also did an update to tpm2-scripts:
https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/tpm2-scripts.git/
See the tip commit. That explains my ASN.1 testing issues. Now that test script fully works again in all of my machines.
Lessons learned, or more like, how do we disclose this kind of testing issue in future: I suggest that we migrate keyctl-smoke.sh (can be possibly renamed) to the kernel selftests, and keep it up to date.
It would also degrade possible stability issues in trusted keys if everyone has standard point of reference.
Thoughts?
/Jarkko
linux-stable-mirror@lists.linaro.org
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Jarkko Sakkinen