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Subject: Re: [PATCH] kexec_buffer measure
To:     Casey Schaufler <casey@schaufler-ca.com>,
        Mimi Zohar <zohar@linux.ibm.com>,
        prakhar srivastava <prsriva02@gmail.com>
Cc:     linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-security-module <linux-security-module@vger.kernel.org>,
        Paul Moore <paul@paul-moore.com>,
        John Johansen <john.johansen@canonical.com>
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From:   Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Message-ID: <5490e443-b3ea-876e-a6b3-6a91005afe61@I-love.SAKURA.ne.jp>
Date:   Fri, 3 May 2019 09:53:49 +0900
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On 2019/05/03 1:28, Casey Schaufler wrote:
> On 5/2/2019 8:48 AM, Mimi Zohar wrote:
>> [Cc'ing Paul, John, Casey]
>>
>> On Mon, 2019-04-22 at 20:18 -0400, Mimi Zohar wrote:
>>> [Cc'ing LSM mailing list]
>>>
>>> On Fri, 2019-04-19 at 17:30 -0700, prakhar srivastava wrote:
>>>
>>>> 2) Adding a LSM hook
>>>> We are doing both the command line and kernel version measurement in IMA.
>>>> Can you please elaborate on how this can be used outside of the scenario?
>>>> That will help me come back with a better design and code. I am
>>>> neutral about this.
>>> As I said previously, initially you might want to only measure the
>>> kexec boot command line, but will you ever want to verify or audit log
>>> the boot command line hash? Perhaps LSMs would be interested in the
>>> boot command line. Should this be an LSM hook?
>>   From an LSM perspective, is there any interest in the boot command line?
> 
> I can imagine an LSM that cares about the command line,
> but I don't have interest in it for any work I have in progress.
> 

Since the kernel command line controls which LSMs to enable, I doubt that
an LSM which cares about the command line can detect that the kernel command
line was tampered when the kernel command line was tampered...