Message-ID: <2dcc460c-73ff-d468-0c43-63ccbe0c4f9e@linux.ibm.com>
Date:   Mon, 6 Mar 2023 11:16:43 -0500
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Subject: Re: [PATCH 21/28] security: Introduce inode_post_remove_acl hook
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To:     Roberto Sassu <roberto.sassu@huaweicloud.com>,
        viro@zeniv.linux.org.uk, chuck.lever@oracle.com,
        jlayton@kernel.org, zohar@linux.ibm.com, dmitry.kasatkin@gmail.com,
        paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com,
        dhowells@redhat.com, jarkko@kernel.org,
        stephen.smalley.work@gmail.com, eparis@parisplace.org,
        casey@schaufler-ca.com, brauner@kernel.org
Cc:     linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
        linux-integrity@vger.kernel.org,
        linux-security-module@vger.kernel.org, keyrings@vger.kernel.org,
        selinux@vger.kernel.org, linux-kernel@vger.kernel.org,
        Roberto Sassu <roberto.sassu@huawei.com>
References: <20230303181842.1087717-1-roberto.sassu@huaweicloud.com>
 <20230303181842.1087717-22-roberto.sassu@huaweicloud.com>
 <6393eb31-5eb3-cb1c-feb7-2ab347703042@linux.ibm.com>
 <7bde74e6e5ccf24b2a2bd9dc2bbfcae5c424eac7.camel@huaweicloud.com>
From:   Stefan Berger <stefanb@linux.ibm.com>
In-Reply-To: <7bde74e6e5ccf24b2a2bd9dc2bbfcae5c424eac7.camel@huaweicloud.com>
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On 3/6/23 10:34, Roberto Sassu wrote:
> On Mon, 2023-03-06 at 10:22 -0500, Stefan Berger wrote:
>>
>> On 3/3/23 13:18, Roberto Sassu wrote:
>>> From: Roberto Sassu <roberto.sassu@huawei.com>
>>>
>>> In preparation for moving IMA and EVM to the LSM infrastructure, introduce
>>> the inode_post_remove_acl hook.
>>>
>>> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
>>> ---
>>>    
>>> +/**
>>> + * security_inode_post_remove_acl() - Update inode sec after remove_acl op
>>> + * @idmap: idmap of the mount
>>> + * @dentry: file
>>> + * @acl_name: acl name
>>> + *
>>> + * Update inode security field after successful remove_acl operation on @dentry
>>> + * in @idmap. The posix acls are identified by @acl_name.
>>> + */
>>> +void security_inode_post_remove_acl(struct mnt_idmap *idmap,
>>> +				    struct dentry *dentry, const char *acl_name)
>>> +{
>>> +	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
>>> +		return;
>>
>> Was that a mistake before that EVM and IMA functions did not filtered out private inodes?
> 
> Looks like that. At least for hooks that are not called from
> security.c.

It seems like that all security_* functions are filtering on private inodes. Anonymous inodes have them and some filesystem set the S_PRIVATE flag. So it may not make a difference fro IMA and EVM then.

     Stefan

> 
> Thanks
> 
> Roberto
>