Re: [TOMOYO #9 (2.6.27-rc7-mm1) 1/6] LSM adapter functions.

[Kentaro Takeda <takedakn@nttdata.co.jp>]

Serge E. Hallyn wrote:
> Why can't you just clear the value during security_inode_foo()?
We need a new hook for clearing the value since security_inode_*() 
are not always called after security_path_*() .

> Note I'm seeing this as a way for Tomoyo to temporarily (maybe) work
> around the mis-placement of the security_path_foo() hooks.  I don't want
> to add security_path_clear() hooks to "legitimize" the workaround.  I'd
> rather Tomoyo and Apparmor folks keep looking for a better way to get
> real DAC-before-MAC.
Hmm, I can understand your opinion. The best way for AppArmor and 
TOMOYO is to pass vfsmount to vfs_*() and security_inode_*() . This 
approach has no DAC-before-MAC problem. However, it is clearly 
opposed by Al because of layering. So, we are going forward 
security_path_*() approach, which Al advised us.

Since vfsmount is only available outside vfs_*() (and vfs_*() perform 
DAC), we cannot conceive another place now... Where do you think the 
right place to introduce security_path_*() hooks is?

Regards,