On Fri, 08 Feb 2008 16:04:29 +0000 David Howells <[EMAIL PROTECTED]> wrote:
> Check the starting keyring as part of the search to (a) see if that is what > we're searching for, and (b) to check it is still valid for searching. > > The scenario: User in process A does things that cause things to be > created in its process session keyring. The user then does an su to > another user and starts a new process, B. The two processes now > share the same process session keyring. > > Process B does an NFS access which results in an upcall to gssd. > When gssd attempts to instantiate the context key (to be linked > into the process session keyring), it is denied access even though it > has an authorization key. > > The order of calls is: > > keyctl_instantiate_key() > lookup_user_key() (the default: case) > search_process_keyrings(current) > search_process_keyrings(rka->context) (recursive call) > keyring_search_aux() > > keyring_search_aux() verifies the keys and keyrings underneath the > top-level keyring it is given, but that top-level keyring is neither > fully validated nor checked to see if it is the thing being searched for. > > This patch changes keyring_search_aux() to: > 1) do more validation on the top keyring it is given and > 2) check whether that top-level keyring is the thing being searched for > > ... > > + (keyring->expiry && now.tv_sec >= keyring->expiry)) time_after()? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
