Re: [PATCH v6 1/5] tpm: Return on tpm2_create_null_primary() failure

[Jarkko Sakkinen]

On Tue Oct 15, 2024 at 11:58 PM EEST, Jarkko Sakkinen wrote:
> tpm2_sessions_init() does not ignore the result of
> tpm2_create_null_primary(). Address this by returning -ENODEV to the
> caller. Given that upper layers cannot help healing the situation
> further, deal with the TPM error here by
>
> Cc: stable@xxxxxxxxxxxxxxx # v6.10+
> Fixes: d2add27cf2b8 ("tpm: Add NULL primary creation")
> Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> ---
> v6:
> - Address:
>   https://lore.kernel.org/linux-integrity/69c893e7-6b87-4daa-80db-44d1120e80fe@xxxxxxxxxxxxx/
>   as TPM RC is taken care of at the call site. Add also the missing
>   documentation for the return values.
> v5:
> - Do not print klog messages on error, as tpm2_save_context() already
>   takes care of this.
> v4:
> - Fixed up stable version.
> v3:
> - Handle TPM and POSIX error separately and return -ENODEV always back
>   to the caller.
> v2:
> - Refined the commit message.
> ---
>  drivers/char/tpm/tpm2-sessions.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c
> index 511c67061728..253639767c1e 100644
> --- a/drivers/char/tpm/tpm2-sessions.c
> +++ b/drivers/char/tpm/tpm2-sessions.c
> @@ -1347,6 +1347,11 @@ static int tpm2_create_null_primary(struct tpm_chip *chip)
>   *
>   * Derive and context save the null primary and allocate memory in the
>   * struct tpm_chip for the authorizations.
> + *
> + * Return:
> + * * 0		- OK
> + * * -errno	- A system error
> + * * TPM_RC	- A TPM error
>   */
>  int tpm2_sessions_init(struct tpm_chip *chip)
>  {
> @@ -1354,7 +1359,7 @@ int tpm2_sessions_init(struct tpm_chip *chip)
>  
>  	rc = tpm2_create_null_primary(chip);
>  	if (rc)
> -		dev_err(&chip->dev, "TPM: security failed (NULL seed derivation): %d\n", rc);

I can fixup this message back before sending PR.

> +		return rc;
>  
>  	chip->auth = kmalloc(sizeof(*chip->auth), GFP_KERNEL);
>  	if (!chip->auth)

I don't know what happened to the cover letter but this version is only
major tweaks to the previous version.

BR, Jarkko