On Fri Sep 13, 2024 at 11:05 PM EEST, Ross Philipson wrote: > From: "Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx> > > The function tpm_tis_request_locality() is expected to return the locality > value that was requested, or a negative error code upon failure. If it is called > while locality_count of struct tis_data is non-zero, no actual locality request > will be sent. Because the ret variable is initially set to 0, the > locality_count will still get increased, and the function will return 0. For a > caller, this would indicate that locality 0 was successfully requested and not > the state changes just mentioned. > > Additionally, the function __tpm_tis_request_locality() provides inconsistent > error codes. It will provide either a failed IO write or a -1 should it have > timed out waiting for locality request to succeed. > > This commit changes __tpm_tis_request_locality() to return valid negative error > codes to reflect the reason it fails. It then adjusts the return value check in > tpm_tis_request_locality() to check for a non-negative return value before > incrementing locality_cout. In addition, the initial value of the ret value is > set to a negative error to ensure the check does not pass if > __tpm_tis_request_locality() is not called. Tweaked version attached with cruft removed and story cleared. BR, Jarkko
From fd307fda578e04e4defb6e0ff47f8fe28a999d4a Mon Sep 17 00:00:00 2001 From: "Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx> Date: Fri, 13 Sep 2024 13:05:13 -0700 Subject: [PATCH] tpm: Support multiple localities in tpm_tis_request_locality() Validate that the input locality is within the correct range, as specified by TCG standards, and increase the locality count also for the positive return values. Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Ross Philipson <ross.philipson@xxxxxxxxxx> Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> --- drivers/char/tpm/tpm_tis_core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 3517db710423..75fb59df75a3 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -234,10 +234,13 @@ static int tpm_tis_request_locality(struct tpm_chip *chip, int l) struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); int ret = 0; + if (l < 0 || l > TPM_MAX_LOCALITY) + return -EINVAL; + mutex_lock(&priv->locality_count_mutex); if (priv->locality_count == 0) ret = __tpm_tis_request_locality(chip, l); - if (!ret) + if (ret >= 0) priv->locality_count++; mutex_unlock(&priv->locality_count_mutex); return ret; -- 2.47.0
