| Message ID | 20240913200517.3085794-15-ross.philipson@oracle.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | x86: Trenchboot secure dynamic launch Linux kernel support | expand |
On Fri Sep 13, 2024 at 11:05 PM EEST, Ross Philipson wrote: > From: "Daniel P. Smith" <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> Remove reported-by. > --- > 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 fdef214b9f6b..a6967f312837 100644 > --- a/drivers/char/tpm/tpm_tis_core.c > +++ b/drivers/char/tpm/tpm_tis_core.c > @@ -180,7 +180,10 @@ 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--; > + else > + pr_info("Invalid: locality count dropped below zero\n"); Explain the context. > if (priv->locality_count == 0) > __tpm_tis_relinquish_locality(priv, l); > mutex_unlock(&priv->locality_count_mutex); BR, Jarkko
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index fdef214b9f6b..a6967f312837 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -180,7 +180,10 @@ 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--; + else + pr_info("Invalid: locality count dropped below zero\n"); if (priv->locality_count == 0) __tpm_tis_relinquish_locality(priv, l); mutex_unlock(&priv->locality_count_mutex);