On Mon, Sep 22, 2025 at 11:25:42AM +0200, Stefano Garzarella wrote:
> On Mon, Sep 22, 2025 at 10:23:32AM +0300, Jarkko Sakkinen wrote:
> > From: Jarkko Sakkinen <[email protected]>
> >
> > Using -EFAULT here was not the best idea for tpm_ret_to_err as the fallback
> > error code as it is no concise with trusted keys.
> >
> > Change the fallback as -EPERM, process TPM_RC_HASH also in tpm_ret_to_err,
> > and by these changes make the helper applicable for trusted keys.
> >
> > Cc: [email protected] # v6.15+
> > Fixes: 539fbab37881 ("tpm: Mask TPM RC in tpm2_start_auth_session()")
> > Signed-off-by: Jarkko Sakkinen <[email protected]>
> > ---
> > include/linux/tpm.h | 9 +++++---
> > security/keys/trusted-keys/trusted_tpm2.c | 26 ++++++-----------------
> > 2 files changed, 13 insertions(+), 22 deletions(-)
> >
> > diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> > index dc0338a783f3..667d290789ca 100644
> > --- a/include/linux/tpm.h
> > +++ b/include/linux/tpm.h
> > @@ -449,13 +449,16 @@ static inline ssize_t tpm_ret_to_err(ssize_t ret)
> > if (ret < 0)
> > return ret;
> >
> > - switch (tpm2_rc_value(ret)) {
> > - case TPM2_RC_SUCCESS:
>
> I slightly prefer the `case TPM2_RC_SUCCESS` but I don't have a strong
> opinion.
>
> > + if (!ret)
> > return 0;
>
> If we want to remove the `case TPM2_RC_SUCCESS`, can we just merge this
> condition with the if on top, I mean:
>
> if (ret <= 0)
> return ret;
I can cope with this i.e. revert back, it's not really part of the scope
and was totally intentional
>
> > +
> > + switch (tpm2_rc_value(ret)) {
> > case TPM2_RC_SESSION_MEMORY:
> > return -ENOMEM;
> > + case TPM2_RC_HASH:
> > + return -EINVAL;
> > default:
> > - return -EFAULT;
> > + return -EPERM;
> > }
> > }
> >
> > diff --git a/security/keys/trusted-keys/trusted_tpm2.c
> > b/security/keys/trusted-keys/trusted_tpm2.c
> > index 024be262702f..e165b117bbca 100644
> > --- a/security/keys/trusted-keys/trusted_tpm2.c
> > +++ b/security/keys/trusted-keys/trusted_tpm2.c
> > @@ -348,25 +348,19 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
> > }
> >
> > blob_len = tpm2_key_encode(payload, options, &buf.data[offset],
> > blob_len);
> > + if (blob_len < 0)
> > + rc = blob_len;
> >
> > out:
> > tpm_buf_destroy(&sized);
> > tpm_buf_destroy(&buf);
> >
> > - if (rc > 0) {
> > - if (tpm2_rc_value(rc) == TPM2_RC_HASH)
> > - rc = -EINVAL;
> > - else
> > - rc = -EPERM;
> > - }
> > - if (blob_len < 0)
>
> nit: since `blob_len` is not accessed anymore in the error path, can we
> avoid to set it to 0 when declaring it?
>
> Thanks,
> Stefano
>
> > - rc = blob_len;
> > - else
> > + if (!rc)
> > payload->blob_len = blob_len;
> >
> > out_put:
> > tpm_put_ops(chip);
> > - return rc;
> > + return tpm_ret_to_err(rc);
> > }
> >
> > /**
> > @@ -468,10 +462,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
> > kfree(blob);
> > tpm_buf_destroy(&buf);
> >
> > - if (rc > 0)
> > - rc = -EPERM;
> > -
> > - return rc;
> > + return tpm_ret_to_err(rc);
> > }
> >
> > /**
> > @@ -534,8 +525,6 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
> > tpm_buf_fill_hmac_session(chip, &buf);
> > rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing");
> > rc = tpm_buf_check_hmac_response(chip, &buf, rc);
> > - if (rc > 0)
> > - rc = -EPERM;
> >
> > if (!rc) {
> > data_len = be16_to_cpup(
> > @@ -568,7 +557,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
> >
> > out:
> > tpm_buf_destroy(&buf);
> > - return rc;
> > + return tpm_ret_to_err(rc);
> > }
> >
> > /**
> > @@ -600,6 +589,5 @@ int tpm2_unseal_trusted(struct tpm_chip *chip,
> >
> > out:
> > tpm_put_ops(chip);
> > -
> > - return rc;
> > + return tpm_ret_to_err(rc);
> > }
> > --
> > 2.39.5
> >
>
BR, Jarkko
