Re: [PATCH] capabilities: Ambient capability set V1

["Serge E. Hallyn" <serge@hallyn.com>]

On Thu, Feb 26, 2015 at 03:23:35PM -0600, Christoph Lameter wrote:
> On Thu, 26 Feb 2015, Serge E. Hallyn wrote:
> 
> > No.  fE is not "not available".  If you set it with setcap, you *should*
> > (if i'm tinking right) find fE full when calculating the new capability
> > sets, because of magic_etc.
> 
> There is nothing in get_vfs_caps_from_disk that does this and the magic
> vanishes after this function is done.

get_vfs_caps_from_disk does:

        cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc);

then bprm_caps_from_vfs_caps does:

        if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE)
                *effective = true;

and finally cap_bprm_set_creds does:

        if (effective)
                new->cap_effective = new->cap_permitted;
        else
                cap_clear(new->cap_effective);