From: Denis Efremov <efremov@linux.com>
To: Roberto Sassu <roberto.sassu@huawei.com>,
Mimi Zohar <zohar@linux.ibm.com>,
"linux-integrity@vger.kernel.org"
<linux-integrity@vger.kernel.org>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>,
Silviu Vlasceanu <Silviu.Vlasceanu@huawei.com>
Subject: Re: IMA/EVM interfaces
Date: Thu, 30 Jul 2020 00:59:10 +0300 [thread overview]
Message-ID: <b3d93ebd-80a0-4aea-15ef-8bd22241e19f@linux.com> (raw)
In-Reply-To: <ef2745fddaec4f859cf9852028f650df@huawei.com>
On 7/28/20 6:43 PM, Roberto Sassu wrote:
>> From: linux-integrity-owner@vger.kernel.org [mailto:linux-integrity-
>> owner@vger.kernel.org] On Behalf Of Denis Efremov
>> Sent: Tuesday, July 28, 2020 12:32 PM
>> Hi,
>>
>> I've started to add integrity interfaces descriptions to syzkaller
>> (https://github.com/google/syzkaller/pull/1970).
>>
>> I've got a question, if you don't mind:
>>
>> If I write 2 to /sys/kernel/security/integrity/evm/evm before loading keys,
>> subsequent fs operations will fail with -ENOKEY.
>>
>> $ echo 2 > /sys/kernel/security/integrity/evm/evm
>> $ touch test.txt
>> [ 526.976855][ T5771] evm: HMAC key is not set
>> [ 526.977892][ T5771] evm: init_desc failed
>> touch: cannot touch 'test.txt': Required key not available
>>
>> Is this a desired behavior? Should there be a check in evm_write_key()
>> for loaded keys (encrypted evm-key, keys in _evm, _ima keyrings) before
>> changing the evm_initialized bit? Is it correct to set second bit without
>> first bit?
>
> Hi Denis
>
> can you please try this patch?
>
> https://lore.kernel.org/linux-integrity/20200618160133.937-1-roberto.sassu@huawei.com/
>
>
$ cat /proc/cmdline
console=ttyS0 root=/dev/sda earlyprintk=serial ima_appraise=fix evm=fix
$ echo 2 > /sys/kernel/security/integrity/evm/evm
[ 44.116084][ T4108] evm: HMAC key is not set
$ touch test.txt
$ cat /sys/kernel/security/integrity/evm/evm
2
$ keyctl add user kmk-user "`cat /etc/keys/kmk-user.blob`" @u
$ keyctl add encrypted evm-key "load `cat /etc/keys/evm-user.blob`" @u
$ echo 1 > /sys/kernel/security/integrity/evm/evm
[ 574.328262] evm: key initialized
Regards,
Denis
next prev parent reply other threads:[~2020-07-29 21:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-28 10:32 IMA/EVM interfaces Denis Efremov
2020-07-28 15:43 ` Roberto Sassu
2020-07-29 21:59 ` Denis Efremov [this message]
2020-07-30 6:50 ` Roberto Sassu
2020-07-31 18:45 ` Mimi Zohar
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