• David Howells's avatar
    KEYS: Add invalidation support · fd75815f
    David Howells authored
    
    
    Add support for invalidating a key - which renders it immediately invisible to
    further searches and causes the garbage collector to immediately wake up,
    remove it from keyrings and then destroy it when it's no longer referenced.
    
    It's better not to do this with keyctl_revoke() as that marks the key to start
    returning -EKEYREVOKED to searches when what is actually desired is to have the
    key refetched.
    
    To invalidate a key the caller must be granted SEARCH permission by the key.
    This may be too strict.  It may be better to also permit invalidation if the
    caller has any of READ, WRITE or SETATTR permission.
    
    The primary use for this is to evict keys that are cached in special keyrings,
    such as the DNS resolver or an ID mapper.
    
    Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
    fd75815f