[RFC PATCH 2/4] tpm, tpm_tis: Address positive localities in tpm_tis_request_locality()

[Jarkko Sakkinen <jarkko@kernel.org>]

From: "Daniel P. Smith" <dpsmith@apertussolutions.com>

Validate that the input locality is within the correct range, as specified
by TCG standards, and increase the locality count also for the positive
localities.

Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
 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 c58f360fb4a4..c86100ad743a 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