[PATCH v17 05/10] fs,landlock: Support filesystem access-control

[Mickaël Salaün]

On 14/05/2020 17:58, Casey Schaufler wrote:
> On 5/14/2020 3:39 AM, Mickaël Salaün wrote:
>> On 14/05/2020 05:37, James Morris wrote:
>>> On Mon, 11 May 2020, Mickaël Salaün wrote:
>>>
>>>
>>>> diff --git a/include/linux/fs.h b/include/linux/fs.h
>>>> index 45cc10cdf6dd..2276642f8e05 100644
>>>> --- a/include/linux/fs.h
>>>> +++ b/include/linux/fs.h
>>>> @@ -1517,6 +1517,11 @@ struct super_block {
>>>>  	/* Pending fsnotify inode refs */
>>>>  	atomic_long_t s_fsnotify_inode_refs;
>>>>  
>>>> +#ifdef CONFIG_SECURITY_LANDLOCK
>>>> +	/* References to Landlock underlying objects */
>>>> +	atomic_long_t s_landlock_inode_refs;
>>>> +#endif
>>>> +
>>> This needs to be converted to the LSM API via superblock blob stacking.
>>>
>>> See Casey's old patch: 
>>> https://lore.kernel.org/linux-security-module/20190829232935.7099-2-casey@schaufler-ca.com/
>> s_landlock_inode_refs is quite similar to s_fsnotify_inode_refs, but I
>> can do it once the superblock security blob patch is upstream. Is it a
>> blocker for now? What is the current status of lbs_superblock?
> 
> As no currently stackable modules conflict over the superblock
> (SELinux and Smack are the existing users) there has been no need
> to move its management into the infrastructure. The active push for
> stacking does not (yet) include everything needed for SELinux+Smack.
> It includes what is needed for SELinux+AppArmor and Smack+AppArmor.
> That does not include the superblock blob.
> 
> You can include a patch in the landlock set that provides infrastructure
> management of the superblock blob. Feel free to glean it from my proposal.

OK, I'll add it to the next series.