Re: LSM hook addition?

[Chris Wright <chrisw@osdl.org>]

* John Richard Moser (nigelenki@comcast.net) wrote:
> Can someone point me to documentation or give me a small patch to add an
> LSM hook to kernel 2.6.10 in fs/namei.c at line 1986:
> 
>         new_dentry = lookup_create(&nd, 0);
>         error = PTR_ERR(new_dentry);
>         if (!IS_ERR(new_dentry)) {
>                 error = security_inode_make_hardlink(old_nd); // ADD
>                 error = vfs_link(old_nd.dentry, nd.dentry->d_inode,
> new_dentry);

It's already there.  Look at the code in vfs_link.  The security_inode_link
hook is documented in include/linux/security.h.  And the restrictive policy
you're referring to is already codified in the owlsm module.  See the
do_owlsm_link() function here (code's a bit old, but basic idea is still
relevant):

http://lsm.bkbits.net:8080/lsm-2.6/anno/security/owlsm.h@1.9?nav=index.html|src/|src/security

thanks,
-chris
-- 
Linux Security Modules     http://lsm.immunix.org     http://lsm.bkbits.net