Move allocation of chip->auth to tpm2_start_auth_session() so that the
field can be used as flag to tell whether auth session is active or not.
Cc: stable@xxxxxxxxxxxxxxx # v6.10+
Fixes: 699e3efd6c64 ("tpm: Add HMAC session start and end functions")
Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
---
v5:
- No changes.
v4:
- Change to bug.
v3:
- No changes.
v2:
- A new patch.
---
drivers/char/tpm/tpm2-sessions.c | 43 +++++++++++++++++++-------------
1 file changed, 25 insertions(+), 18 deletions(-)
diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c
index 78c650ce4c9f..6e52785de9fd 100644
--- a/drivers/char/tpm/tpm2-sessions.c
+++ b/drivers/char/tpm/tpm2-sessions.c
@@ -484,7 +484,8 @@ static void tpm2_KDFe(u8 z[EC_PT_SZ], const char *str, u8 *pt_u, u8 *pt_v,
sha256_final(&sctx, out);
}
-static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip)
+static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip,
+ struct tpm2_auth *auth)
{
struct crypto_kpp *kpp;
struct kpp_request *req;
@@ -543,7 +544,7 @@ static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip)
sg_set_buf(&s[0], chip->null_ec_key_x, EC_PT_SZ);
sg_set_buf(&s[1], chip->null_ec_key_y, EC_PT_SZ);
kpp_request_set_input(req, s, EC_PT_SZ*2);
- sg_init_one(d, chip->auth->salt, EC_PT_SZ);
+ sg_init_one(d, auth->salt, EC_PT_SZ);
kpp_request_set_output(req, d, EC_PT_SZ);
crypto_kpp_compute_shared_secret(req);
kpp_request_free(req);
@@ -554,8 +555,7 @@ static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip)
* This works because KDFe fully consumes the secret before it
* writes the salt
*/
- tpm2_KDFe(chip->auth->salt, "SECRET", x, chip->null_ec_key_x,
- chip->auth->salt);
+ tpm2_KDFe(auth->salt, "SECRET", x, chip->null_ec_key_x, auth->salt);
out:
crypto_free_kpp(kpp);
@@ -854,6 +854,8 @@ int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf,
/* manually close the session if it wasn't consumed */
tpm2_flush_context(chip, auth->handle);
memzero_explicit(auth, sizeof(*auth));
+ kfree(auth);
+ chip->auth = NULL;
} else {
/* reset for next use */
auth->session = TPM_HEADER_SIZE;
@@ -882,6 +884,8 @@ void tpm2_end_auth_session(struct tpm_chip *chip)
tpm2_flush_context(chip, auth->handle);
memzero_explicit(auth, sizeof(*auth));
+ kfree(auth);
+ chip->auth = NULL;
}
EXPORT_SYMBOL(tpm2_end_auth_session);
@@ -970,25 +974,29 @@ static int tpm2_load_null(struct tpm_chip *chip, u32 *null_key)
*/
int tpm2_start_auth_session(struct tpm_chip *chip)
{
+ struct tpm2_auth *auth;
struct tpm_buf buf;
- struct tpm2_auth *auth = chip->auth;
- int rc;
u32 null_key;
+ int rc;
- if (!auth) {
- dev_warn_once(&chip->dev, "auth session is not active\n");
+ if (chip->auth) {
+ dev_warn_once(&chip->dev, "auth session is active\n");
return 0;
}
+ auth = kzalloc(sizeof(*auth), GFP_KERNEL);
+ if (!auth)
+ return -ENOMEM;
+
rc = tpm2_load_null(chip, &null_key);
if (rc)
- goto out;
+ goto err;
auth->session = TPM_HEADER_SIZE;
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_START_AUTH_SESS);
if (rc)
- goto out;
+ goto err;
/* salt key handle */
tpm_buf_append_u32(&buf, null_key);
@@ -1000,7 +1008,7 @@ int tpm2_start_auth_session(struct tpm_chip *chip)
tpm_buf_append(&buf, auth->our_nonce, sizeof(auth->our_nonce));
/* append encrypted salt and squirrel away unencrypted in auth */
- tpm_buf_append_salt(&buf, chip);
+ tpm_buf_append_salt(&buf, chip, auth);
/* session type (HMAC, audit or policy) */
tpm_buf_append_u8(&buf, TPM2_SE_HMAC);
@@ -1021,10 +1029,13 @@ int tpm2_start_auth_session(struct tpm_chip *chip)
tpm_buf_destroy(&buf);
- if (rc)
- goto out;
+ if (rc == TPM2_RC_SUCCESS) {
+ chip->auth = auth;
+ return 0;
+ }
- out:
+err:
