Comment 20 for bug 212485

void rpcb_getport_async(struct rpc_task *task)
{
        struct rpc_clnt *clnt = task->tk_client;
        int bind_version;
        struct rpc_xprt *xprt = task->tk_xprt;
        struct rpc_clnt *rpcb_clnt;
        static struct rpcbind_args *map;
        struct rpc_task *child;
        struct sockaddr addr;
        int status;
        struct rpcb_info *info;

        dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
                task->tk_pid, __FUNCTION__,
                clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);

        /* Autobind on cloned rpc clients is discouraged */
        BUG_ON(clnt->cl_parent != clnt); <------

This is triggering I believe due to memory corruption. Confirming with NFS developers any patches which address memory corruption related to this, eg:

http://groups.google.co.uk/group/linux.kernel/browse_thread/thread/599db16a8d9d84ed#