[PATCH 2/3] selinux: Implement the object_init_security hook

[Paul Moore]

On Wed, Jan 9, 2019 at 9:38 AM Stephen Smalley <sds at tycho.nsa.gov> wrote:
> On 1/9/19 4:10 AM, Ondrej Mosnacek wrote:
> > The hook applies the same logic as selinux_determine_inode_label(), with
> > the exception of the super_block handling, which will be enforced on the
> > actual inodes by other hooks.
> >
> > Signed-off-by: Ondrej Mosnacek <omosnace at redhat.com>
>
> Reviewed-by: Stephen Smalley <sds at tycho.nsa.gov>

Looks good to me too.

> > ---
> >   security/selinux/hooks.c | 41 ++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 41 insertions(+)
> >
> > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> > index 7ce012d9ec51..29c038513504 100644
> > --- a/security/selinux/hooks.c
> > +++ b/security/selinux/hooks.c
> > @@ -3526,6 +3526,45 @@ static int selinux_inode_copy_up_xattr(const char *name)
> >       return -EOPNOTSUPP;
> >   }
> >
> > +/* file-like object operations */
> > +
> > +/* Used e.g. for kernfs_node for newly created nodes */
> > +static int selinux_object_init_security(void *parent_ctx, u32 parent_ctxlen,
> > +                                     const struct qstr *qstr, u16 mode,
> > +                                     void **ctx, u32 *ctxlen)
> > +{
> > +     const struct task_security_struct *tsec = current_security();
> > +     u32 parent_sid, newsid, clen;
> > +     int rc;
> > +     char *context;
> > +
> > +     rc = security_context_to_sid(&selinux_state, parent_ctx, parent_ctxlen,
> > +                                  &parent_sid, GFP_KERNEL);
> > +     if (rc)
> > +             return rc;
> > +
> > +     if (tsec->create_sid) {
> > +             newsid = tsec->create_sid;
> > +     } else {
> > +             u16 secclass = inode_mode_to_security_class(mode);
> > +
> > +             rc = security_transition_sid(&selinux_state, tsec->sid,
> > +                                          parent_sid, secclass, qstr,
> > +                                          &newsid);
> > +             if (rc)
> > +                     return rc;
> > +     }
> > +
> > +     rc = security_sid_to_context_force(&selinux_state, newsid,
> > +                                        &context, &clen);
> > +     if (rc)
> > +             return rc;
> > +
> > +     *ctx = context;
> > +     *ctxlen = clen;
> > +     return 0;
> > +}
> > +
> >   /* file security operations */
> >
> >   static int selinux_revalidate_file_permission(struct file *file, int mask)
> > @@ -6965,6 +7004,8 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
> >       LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
> >       LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
> >
> > +     LSM_HOOK_INIT(object_init_security, selinux_object_init_security),
> > +
> >       LSM_HOOK_INIT(file_permission, selinux_file_permission),
> >       LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
> >       LSM_HOOK_INIT(file_free_security, selinux_file_free_security),
> >
>


-- 
paul moore
www.paul-moore.com