[PATCH 1/2] KEYS: Replace uid/gid/perm permissions checking with an ACL

[Eric Biggers]

On Tue, Aug 06, 2019 at 07:58:14PM -0700, Eric Biggers wrote:
> On Tue, Jul 30, 2019 at 06:16:14PM -0700, Eric Biggers wrote:
> > On Mon, Jul 29, 2019 at 08:49:56PM -0700, Eric Biggers wrote:
> > > Hi David,
> > > 
> > > On Tue, Jul 09, 2019 at 06:16:01PM -0700, Eric Biggers wrote:
> > > > On Thu, May 23, 2019 at 04:58:27PM +0100, David Howells wrote:
> > > > > Replace the uid/gid/perm permissions checking on a key with an ACL to allow
> > > > > the SETATTR and SEARCH permissions to be split.  This will also allow a
> > > > > greater range of subjects to represented.
> > > > > 
> > > > 
> > > > This patch broke 'keyctl new_session', and hence broke all the fscrypt tests:
> > > > 
> > > > $ keyctl new_session
> > > > keyctl_session_to_parent: Permission denied
> > > > 
> > > > Output of 'keyctl show' is
> > > > 
> > > > $ keyctl show
> > > > Session Keyring
> > > >  605894913 --alswrv      0     0  keyring: _ses
> > > >  189223103 ----s-rv      0     0   \_ user: invocation_id
> > > > 
> > > > - Eric
> > > 
> > > This bug is still present in next-20190729.
> > > 
> > > - Eric
> > 
> > This fixes it:
> > 
> > diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
> > index aa3bfcadbc660..519c94f1cc3c2 100644
> > --- a/security/keys/process_keys.c
> > +++ b/security/keys/process_keys.c
> > @@ -58,7 +58,7 @@ static struct key_acl session_keyring_acl = {
> >  	.possessor_viewable = true,
> >  	.nr_ace	= 2,
> >  	.aces = {
> > -		KEY_POSSESSOR_ACE(KEY_ACE__PERMS & ~KEY_ACE_JOIN),
> > +		KEY_POSSESSOR_ACE(KEY_ACE__PERMS),
> >  		KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
> >  	}
> >  };
> > 
> > 
> > The old permissions were KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, so
> > I'm not sure why JOIN permission was removed?
> > 
> > - Eric
> 
> Ping.  This is still broken in linux-next.
> 

David, any comment on this?  This is still broken in linux-next.

- Eric