Re: [PATCH v6 17/17] ima: Setup securityfs for IMA namespace

[Mimi Zohar <zohar@linux.ibm.com>]

Hi Stefan, James,

On Fri, 2021-12-10 at 14:47 -0500, Stefan Berger wrote:
> Setup securityfs with symlinks, directories, and files for IMA
> namespacing support. The same directory structure that IMA uses on the
> host is also created for the namespacing case.
> 
> The securityfs file and directory ownerships cannot be set when the
> IMA namespace is initialized. Therefore, delay the setup of the file
> system to a later point when securityfs is in securityfs_fill_super.
> 
> This filesystem can now be mounted as follows:
> 
> mount -t securityfs /sys/kernel/security/ /sys/kernel/security/
> 
> The following directories, symlinks, and files are then available.
> 
> $ ls -l sys/kernel/security/
> total 0
> lr--r--r--. 1 root root 0 Dec  2 00:18 ima -> integrity/ima
> drwxr-xr-x. 3 root root 0 Dec  2 00:18 integrity

The ima symlink was introduced for backwards compatibilty.  Refer to
commit 0c343af8065b ("integrity: Add an integrity directory in
securityfs").  The symlink shouldn't need to be supported in IMA
namespace.

thanks,

Mimi

> 
> $ ls -l sys/kernel/security/ima/
> total 0
> -r--r-----. 1 root root 0 Dec  2 00:18 ascii_runtime_measurements
> -r--r-----. 1 root root 0 Dec  2 00:18 binary_runtime_measurements
> -rw-------. 1 root root 0 Dec  2 00:18 policy
> -r--r-----. 1 root root 0 Dec  2 00:18 runtime_measurements_count
> -r--r-----. 1 root root 0 Dec  2 00:18 violations
> 
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>