From: Mimi Zohar <zohar@linux.ibm.com>
To: Casey Schaufler <casey@schaufler-ca.com>,
linux-integrity <linux-integrity@vger.kernel.org>
Cc: LSM <linux-security-module@vger.kernel.org>
Subject: Re: evm_inode_init_security and module stacking
Date: Thu, 17 Jan 2019 21:31:29 -0500 [thread overview]
Message-ID: <1547778689.3982.20.camel@linux.ibm.com> (raw)
In-Reply-To: <f1a86814-716a-d02d-42ce-8ef64d680feb@schaufler-ca.com>
On Thu, 2019-01-17 at 16:47 -0800, Casey Schaufler wrote:
> security_inode_init_security() currently calls at most one
> of selinux_inode_init_security() and smack_inode_init_security().
> It then sends the result to evm_inode_init_security to create
> the security.evm attribute. This isn't going to work on a system
> that has both SELinux and Smack.
Calculating security.evm based on multiple xattrs sounded really
familiar. Looking back at the git log, 9d8f13ba3f48 ("security: new
security_inode_init_security API adds function callback") addressed
filesystems wanting to be able to write all the xattrs at the same
time and prepared for multiple LSM xattr support.
> I see two options:
> - create security.evm with the information from all
> security modules that provide inode_init_security hooks
> - create a separate attribute for each module,
> security.evm-selinux and security.evm-smack in the
> current case.
>
> How would you like to have it work? I am agnostic, although the
> separate attributes would be easier for the infrastructure.
Having separate attributes for each LSM module would require re-
calculating the hmac for each one, any time any of the other file
metadata changed. That doesn't sound like a good idea.
Mimi
next prev parent reply other threads:[~2019-01-18 2:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-18 0:47 evm_inode_init_security and module stacking Casey Schaufler
2019-01-18 2:31 ` Mimi Zohar [this message]
2019-01-18 18:49 ` Casey Schaufler
2019-01-20 16:42 ` Mimi Zohar
2019-01-20 18:54 ` Casey Schaufler
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