On Mon, Sep 22, 2025 at 07:43:14PM +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.

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:
+       if (!ret)
                return 0;

Fold this into the check above to get:

        if (ret <= 0)

?

+
+       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)
-               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



J.

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