From: "Daniel P. Smith" <dpsmith@apertussolutions.com>
To: Jason Gunthorpe <jgg@ziepe.ca>,
Jarkko Sakkinen <jarkko@kernel.org>,
Sasha Levin <sashal@kernel.org>,
Lino Sanfilippo <l.sanfilippo@kunbus.com>,
linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: "Daniel P. Smith" <dpsmith@apertussolutions.com>,
Ross Philipson <ross.philipson@oracle.com>,
Kanth Ghatraju <kanth.ghatraju@oracle.com>,
Peter Huewe <peterhuewe@gmx.de>
Subject: [PATCH 1/3] tpm: protect against locality counter underflow
Date: Wed, 31 Jan 2024 12:08:21 -0500 [thread overview]
Message-ID: <20240131170824.6183-2-dpsmith@apertussolutions.com> (raw)
In-Reply-To: <20240131170824.6183-1-dpsmith@apertussolutions.com>
Commit 933bfc5ad213 introduced the use of a locality counter to control when a
locality request is allowed to be sent to the TPM. In the commit, the counter
is indiscriminately decremented. Thus creating a situation for an integer
underflow of the counter.
Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
Reported-by: Kanth Ghatraju <kanth.ghatraju@oracle.com>
Fixes: 933bfc5ad213 ("tpm, tpm: Implement usage counter for locality")
---
drivers/char/tpm/tpm_tis_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 1b350412d8a6..4176d3bd1f04 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -180,7 +180,8 @@ static int tpm_tis_relinquish_locality(struct tpm_chip *chip, int l)
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
mutex_lock(&priv->locality_count_mutex);
- priv->locality_count--;
+ if (priv->locality_count > 0)
+ priv->locality_count--;
if (priv->locality_count == 0)
__tpm_tis_relinquish_locality(priv, l);
mutex_unlock(&priv->locality_count_mutex);
--
2.30.2
next parent reply other threads:[~2024-01-31 17:08 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20240131170824.6183-1-dpsmith@apertussolutions.com>
2024-01-31 17:08 ` Daniel P. Smith [this message]
2024-02-01 22:21 ` [PATCH 1/3] tpm: protect against locality counter underflow Jarkko Sakkinen
2024-02-02 3:08 ` Lino Sanfilippo
2024-02-12 20:05 ` Jarkko Sakkinen
2024-02-19 17:54 ` Daniel P. Smith
2024-02-20 18:42 ` Alexander Steffen
2024-02-20 19:04 ` Jarkko Sakkinen
2024-02-20 20:54 ` Lino Sanfilippo
2024-02-20 22:23 ` Jarkko Sakkinen
2024-02-20 23:19 ` Lino Sanfilippo
2024-02-21 0:40 ` Jarkko Sakkinen
2024-02-23 1:58 ` Daniel P. Smith
2024-02-23 12:58 ` Jarkko Sakkinen
2024-02-25 11:23 ` Daniel P. Smith
2024-02-26 9:39 ` Jarkko Sakkinen
2024-02-20 22:26 ` Jarkko Sakkinen
2024-02-20 22:31 ` Jarkko Sakkinen
2024-02-20 23:26 ` Lino Sanfilippo
2024-02-21 0:42 ` Jarkko Sakkinen
2024-02-21 12:37 ` James Bottomley
2024-02-21 19:43 ` Jarkko Sakkinen
2024-02-21 19:45 ` Jarkko Sakkinen
2024-02-22 9:06 ` James Bottomley
2024-02-22 23:49 ` Jarkko Sakkinen
2024-02-23 1:57 ` Daniel P. Smith
2024-02-23 20:40 ` Jarkko Sakkinen
2024-02-23 20:42 ` Jarkko Sakkinen
2024-02-23 1:57 ` Daniel P. Smith
2024-02-23 20:50 ` Jarkko Sakkinen
2024-02-20 22:57 ` ross.philipson
2024-02-20 23:10 ` Jarkko Sakkinen
2024-02-20 23:13 ` Jarkko Sakkinen
2024-02-23 1:56 ` Daniel P. Smith
2024-02-23 20:44 ` Jarkko Sakkinen
2024-02-24 2:34 ` Lino Sanfilippo
2024-02-26 9:38 ` Jarkko Sakkinen
2024-02-23 1:55 ` Daniel P. Smith
2024-02-26 12:43 ` Alexander Steffen
2024-02-24 2:06 ` Lino Sanfilippo
2024-02-23 0:01 ` Jarkko Sakkinen
2024-01-31 17:08 ` [PATCH 2/3] tpm: ensure tpm is in known state at startup Daniel P. Smith
2024-02-01 22:33 ` Jarkko Sakkinen
2024-02-19 19:17 ` Daniel P. Smith
2024-02-19 20:17 ` Jarkko Sakkinen
2024-01-31 17:08 ` [PATCH 3/3] tpm: make locality request return value consistent Daniel P. Smith
2024-02-01 22:49 ` Jarkko Sakkinen
2024-02-19 20:29 ` Daniel P. Smith
2024-02-19 20:45 ` Jarkko Sakkinen
2024-02-20 18:57 ` Alexander Steffen
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