2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: J. Bruce Fields commit 886e3b7fe6054230c89ae078a09565ed183ecc73 upstream. On setting up the callback to the client, we attempt to use the same authentication flavor the client did. We find an rpc cred to use by calling rpcauth_lookup_credcache(), which assumes that the given authentication flavor has a credentials cache. However, this is not required to be true--in particular, auth_null does not use one. Instead, we should call the auth's lookup_cred() method. Without this, a client attempting to mount using nfsv4 and auth_null triggers a null dereference. Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4callback.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -444,6 +444,7 @@ static struct rpc_cred *lookup_cb_cred(s struct auth_cred acred = { .machine_cred = 1 }; + struct rpc_auth *auth = cb->cb_client->cl_auth; /* * Note in the gss case this doesn't actually have to wait for a @@ -451,8 +452,7 @@ static struct rpc_cred *lookup_cb_cred(s * non-uptodate cred which the rpc state machine will fill in with * a refresh_upcall later. */ - return rpcauth_lookup_credcache(cb->cb_client->cl_auth, &acred, - RPCAUTH_LOOKUP_NEW); + return auth->au_ops->lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW); } void do_probe_callback(struct nfs4_client *clp) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/