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Message-ID: <6f0e04c2-4602-4407-9af5-f72610021a6a@linux.ibm.com>
Date: Tue, 4 Jun 2024 14:41:44 -0400
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Subject: Re: [PATCH v7 3/5] crypto: tpm2_key: Introduce a TPM2 key type
To: Jarkko Sakkinen <jarkko@kernel.org>,
        Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-integrity@vger.kernel.org, keyrings@vger.kernel.org,
        Andreas.Fuchs@infineon.com, James Prestwood <prestwoj@gmail.com>,
        David Woodhouse <dwmw2@infradead.org>,
        Eric Biggers <ebiggers@kernel.org>,
        James Bottomley <James.Bottomley@hansenpartnership.com>,
        linux-crypto@vger.kernel.org,
        Lennart Poettering <lennart@poettering.net>,
        "David S. Miller" <davem@davemloft.net>,
        open list <linux-kernel@vger.kernel.org>,
        Mimi Zohar <zohar@linux.ibm.com>, David Howells <dhowells@redhat.com>,
        Paul Moore <paul@paul-moore.com>, James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        "open list:SECURITY SUBSYSTEM" <linux-security-module@vger.kernel.org>
References: <20240528210823.28798-1-jarkko@kernel.org>
 <20240528210823.28798-4-jarkko@kernel.org>
 <97dd7485-51bf-4e47-83ab-957710fc2182@linux.ibm.com>
 <D1REOCZ2XHRY.4U47RZ20QET1@kernel.org>
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From: Stefan Berger <stefanb@linux.ibm.com>
In-Reply-To: <D1REOCZ2XHRY.4U47RZ20QET1@kernel.org>
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On 6/4/24 13:23, Jarkko Sakkinen wrote:
> On Fri May 31, 2024 at 3:35 AM EEST, Stefan Berger wrote:
>>

>>>    
>>> -	rc = tpm2_key_decode(payload, options, &blob);
>>> -	if (rc) {
>>> -		/* old form */
>>> +	key = tpm2_key_decode(payload->blob, payload->blob_len);
>>> +	if (IS_ERR(key)) {
>>> +		/* Get the error code and reset the pointer to the key: */
>>> +		rc = PTR_ERR(key);
>>> +		key = NULL;
>>> +
>>> +		if (rc == -ENOMEM)
>>> +			return -ENOMEM;
>>> +
>>> +		/* A sanity check, as only -EBADMSG or -ENOMEM are expected: */
>>> +		if (rc != -EBADMSG)
>>> +			pr_err("tpm2_key_decode(): spurious error code %d\n", rc);
>>
>> tpm2_key_decode seems simple enough that it only returns key, -ENOMEM or
>> EBADMSG.
> 
> So what is your suggestion here?

You can remove the check resuling in pr_err().

> 
> The reasoning here is that asymmetric keys use -EBADMSG not only as
> error but also iterator, when probing which can load a specific key.
>