@@ -850,9 +850,10 @@ static int tpm2_parse_start_auth_session(struct tpm2_auth *auth,
static int tpm2_load_null(struct tpm_chip *chip, u32 *null_key)
{
- int rc;
unsigned int offset = 0; /* dummy offset for null seed context */
u8 name[SHA256_DIGEST_SIZE + 2];
+ u32 tmp_null_key;
+ int rc;
rc = tpm2_load_context(chip, chip->null_key_context, &offset,
null_key);
@@ -861,11 +862,17 @@ static int tpm2_load_null(struct tpm_chip *chip, u32 *null_key)
/* an integrity failure may mean the TPM has been reset */
dev_err(&chip->dev, "NULL key integrity failure!\n");
- /* check the null name against what we know */
- tpm2_create_primary(chip, TPM2_RH_NULL, NULL, name);
- if (memcmp(name, chip->null_key_name, sizeof(name)) == 0)
- /* name unchanged, assume transient integrity failure */
+
+ rc = tpm2_create_primary(chip, TPM2_RH_NULL, &tmp_null_key, name);
+ if (rc)
return rc;
+
+ /* Return the null key if the name has not been changed: */
+ if (memcmp(name, chip->null_key_name, sizeof(name)) == 0) {
+ *null_key = tmp_null_key;
+ return 0;
+ }
+
/*
* Fatal TPM failure: the NULL seed has actually changed, so
* the TPM must have been illegally reset. All in-kernel TPM
@@ -874,6 +881,7 @@ static int tpm2_load_null(struct tpm_chip *chip, u32 *null_key)
* userspace programmes can't be compromised by it.
*/
dev_err(&chip->dev, "NULL name has changed, disabling TPM due to interference\n");
+ tpm2_flush_context(chip, tmp_null_key);
chip->flags |= TPM_CHIP_FLAG_DISABLE;
return rc;
@@ -991,10 +999,6 @@ static int tpm2_parse_create_primary(struct tpm_chip *chip, struct tpm_buf *buf,
u32 val, param_len, keyhandle;
keyhandle = tpm_buf_read_u32(buf, &offset_r);
- if (handle)
- *handle = keyhandle;
- else
- tpm2_flush_context(chip, keyhandle);
param_len = tpm_buf_read_u32(buf, &offset_r);
/*
@@ -1135,6 +1139,7 @@ static int tpm2_parse_create_primary(struct tpm_chip *chip, struct tpm_buf *buf,
return -EINVAL;
}
+ *handle = keyhandle;
return 0;
}
tpm2_load_null() ignores the return value of tpm2_create_primary(). Return instead on failure. On success when the null key name has not been changed heal appropriately, and return the created key handle instead of flushing it. Fixes: eb24c9788cd9 ("tpm: disable the TPM if NULL name changes") Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> --- drivers/char/tpm/tpm2-sessions.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-)