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Message-ID: <6154a26bb0efc2abbfc51df4bf1adc8279854f3c.camel@linux.ibm.com>
Subject: Re: [PATCH v10 19/25] integrity: Move
 integrity_kernel_module_request() to IMA
From: Mimi Zohar <zohar@linux.ibm.com>
To: Roberto Sassu <roberto.sassu@huaweicloud.com>, viro@zeniv.linux.org.uk,
        brauner@kernel.org, jack@suse.cz, chuck.lever@oracle.com,
        jlayton@kernel.org, neilb@suse.de, kolga@netapp.com,
        Dai.Ngo@oracle.com, tom@talpey.com, paul@paul-moore.com,
        jmorris@namei.org, serge@hallyn.com, dmitry.kasatkin@gmail.com,
        eric.snowberg@oracle.com, dhowells@redhat.com, jarkko@kernel.org,
        stephen.smalley.work@gmail.com, omosnace@redhat.com,
        casey@schaufler-ca.com, shuah@kernel.org, mic@digikod.net
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-nfs@vger.kernel.org, linux-security-module@vger.kernel.org,
        linux-integrity@vger.kernel.org, keyrings@vger.kernel.org,
        selinux@vger.kernel.org, linux-kselftest@vger.kernel.org,
        Roberto Sassu
	 <roberto.sassu@huawei.com>,
        Stefan Berger <stefanb@linux.ibm.com>
Date: Thu, 15 Feb 2024 19:25:41 -0500
In-Reply-To: <09d6fa08e2d62720759f57237043a2dd9b5208ca.camel@huaweicloud.com>
References: <20240215103113.2369171-1-roberto.sassu@huaweicloud.com>
	 <20240215103113.2369171-20-roberto.sassu@huaweicloud.com>
	 <09d6fa08e2d62720759f57237043a2dd9b5208ca.camel@huaweicloud.com>
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On Thu, 2024-02-15 at 17:09 +0100, Roberto Sassu wrote:
> On Thu, 2024-02-15 at 11:31 +0100, Roberto Sassu wrote:
> > From: Roberto Sassu <roberto.sassu@huawei.com>
> > 
> > In preparation for removing the 'integrity' LSM, move
> > integrity_kernel_module_request() to IMA, and rename it to
> > ima_kernel_module_request(). Rewrite the function documentation, to explain
> > better what the problem is.
> > 
> > Compile it conditionally if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is enabled,
> > and call it from security.c (removed afterwards with the move of IMA to the
> > LSM infrastructure).
> > 
> > Adding this hook cannot be avoided, since IMA has no control on the flags
> > passed to crypto_alloc_sig() in public_key_verify_signature(), and thus
> > cannot pass CRYPTO_NOLOAD, which solved the problem for EVM hashing with
> > commit e2861fa71641 ("evm: Don't deadlock if a crypto algorithm is
> > unavailable").
> > 
> > EVM alone does not need to implement this hook, first because there is no
> > mutex to deadlock, and second because even if it had it, there should be a
> > recursive call. However, since verification from EVM can be initiated only
> > by setting inode metadata, deadlock would occur if modprobe would do the
> > same while loading a kernel module (which is unlikely).
> > 
> > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> > Acked-by: Paul Moore <paul@paul-moore.com>
> > Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
> > Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
> > Acked-by: Mimi Zohar <zohar@linux.ibm.com>
> 
> I hope the change of the ima_kernel_module_request() documentation is
> fine for everyone.
> 
> If not, let me know.

Thanks, Roberto.  The updated kernel-doc looks good.

Mimi