nfsd4: fix bare destroy_session null dereference

[safe/jmp/linux-2.6] / fs / nfsd / nfs4state.c

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index cf650cb..835d6ce 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -34,6 +34,7 @@
 
 #include <linux/file.h>
 #include <linux/smp_lock.h>
+#include <linux/slab.h>
 #include <linux/namei.h>
 #include <linux/swap.h>
 #include <linux/sunrpc/svcauth_gss.h>
@@ -726,8 +727,8 @@ expire_client(struct nfs4_client *clp)
                release_session(ses);
        }
        nfsd4_set_callback_client(clp, NULL);
-       if (clp->cl_cb_xprt)
-               svc_xprt_put(clp->cl_cb_xprt);
+       if (clp->cl_cb_conn.cb_xprt)
+               svc_xprt_put(clp->cl_cb_conn.cb_xprt);
        free_client(clp);
 }
 
@@ -814,7 +815,7 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir,
        }
 
        memcpy(clp->cl_recdir, recdir, HEXDIR_LEN);
-       atomic_set(&clp->cl_cb_conn.cb_set, 0);
+       atomic_set(&clp->cl_cb_set, 0);
        INIT_LIST_HEAD(&clp->cl_idhash);
        INIT_LIST_HEAD(&clp->cl_strhash);
        INIT_LIST_HEAD(&clp->cl_openowners);
@@ -1302,8 +1303,8 @@ nfsd4_create_session(struct svc_rqst *rqstp,
                move_to_confirmed(unconf);
 
                if (cr_ses->flags & SESSION4_BACK_CHAN) {
-                       unconf->cl_cb_xprt = rqstp->rq_xprt;
-                       svc_xprt_get(unconf->cl_cb_xprt);
+                       unconf->cl_cb_conn.cb_xprt = rqstp->rq_xprt;
+                       svc_xprt_get(rqstp->rq_xprt);
                        rpc_copy_addr(
                                (struct sockaddr *)&unconf->cl_cb_conn.cb_addr,
                                sa);
@@ -1312,7 +1313,7 @@ nfsd4_create_session(struct svc_rqst *rqstp,
                                cstate->minorversion;
                        unconf->cl_cb_conn.cb_prog = cr_ses->callback_prog;
                        unconf->cl_cb_seq_nr = 1;
-                       nfsd4_probe_callback(unconf);
+                       nfsd4_probe_callback(unconf, &unconf->cl_cb_conn);
                }
                conf = unconf;
        } else {
@@ -1343,6 +1344,21 @@ out:
        return status;
 }
 
+static bool nfsd4_last_compound_op(struct svc_rqst *rqstp)
+{
+       struct nfsd4_compoundres *resp = rqstp->rq_resp;
+       struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+
+       return argp->opcnt == resp->opcnt;
+}
+
+static bool nfsd4_compound_in_session(struct nfsd4_session *session, struct nfs4_sessionid *sid)
+{
+       if (!session)
+               return 0;
+       return !memcmp(sid, &session->se_sessionid, sizeof(*sid));
+}
+
 __be32
 nfsd4_destroy_session(struct svc_rqst *r,
                      struct nfsd4_compound_state *cstate,
@@ -1358,6 +1374,10 @@ nfsd4_destroy_session(struct svc_rqst *r,
         * - Do we need to clear any callback info from previous session?
         */
 
+       if (nfsd4_compound_in_session(cstate->session, &sessionid->sessionid)) {
+               if (!nfsd4_last_compound_op(r))
+                       return nfserr_not_only_op;
+       }
        dump_sessionid(__func__, &sessionid->sessionid);
        spin_lock(&sessionid_lock);
        ses = find_in_sessionid_hashtbl(&sessionid->sessionid);
@@ -1430,11 +1450,10 @@ nfsd4_sequence(struct svc_rqst *rqstp,
        cstate->slot = slot;
        cstate->session = session;
 
-       /* Hold a session reference until done processing the compound:
-        * nfsd4_put_session called only if the cstate slot is set.
-        */
-       nfsd4_get_session(session);
 out:
+       /* Hold a session reference until done processing the compound. */
+       if (cstate->session)
+               nfsd4_get_session(cstate->session);
        spin_unlock(&sessionid_lock);
        /* Renew the clientid on success and on replay */
        if (cstate->session) {
@@ -1605,9 +1624,8 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
                if (!same_creds(&conf->cl_cred, &unconf->cl_cred))
                        status = nfserr_clid_inuse;
                else {
-                       /* XXX: We just turn off callbacks until we can handle
-                         * change request correctly. */
-                       atomic_set(&conf->cl_cb_conn.cb_set, 0);
+                       atomic_set(&conf->cl_cb_set, 0);
+                       nfsd4_probe_callback(conf, &unconf->cl_cb_conn);
                        expire_client(unconf);
                        status = nfs_ok;
 
@@ -1641,7 +1659,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
                        }
                        move_to_confirmed(unconf);
                        conf = unconf;
-                       nfsd4_probe_callback(conf);
+                       nfsd4_probe_callback(conf, &conf->cl_cb_conn);
                        status = nfs_ok;
                }
        } else if ((!conf || (conf && !same_verf(&conf->cl_confirm, &confirm)))
@@ -2320,7 +2338,7 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta
 {
        struct nfs4_delegation *dp;
        struct nfs4_stateowner *sop = stp->st_stateowner;
-       struct nfs4_cb_conn *cb = &sop->so_client->cl_cb_conn;
+       int cb_up = atomic_read(&sop->so_client->cl_cb_set);
        struct file_lock fl, *flp = &fl;
        int status, flag = 0;
 
@@ -2328,7 +2346,7 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta
        open->op_recall = 0;
        switch (open->op_claim_type) {
                case NFS4_OPEN_CLAIM_PREVIOUS:
-                       if (!atomic_read(&cb->cb_set))
+                       if (!cb_up)
                                open->op_recall = 1;
                        flag = open->op_delegate_type;
                        if (flag == NFS4_OPEN_DELEGATE_NONE)
@@ -2339,7 +2357,7 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta
                         * had the chance to reclaim theirs.... */
                        if (locks_in_grace())
                                goto out;
-                       if (!atomic_read(&cb->cb_set) || !sop->so_confirmed)
+                       if (!cb_up || !sop->so_confirmed)
                                goto out;
                        if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
                                flag = NFS4_OPEN_DELEGATE_WRITE;
@@ -2510,7 +2528,7 @@ nfsd4_renew(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        renew_client(clp);
        status = nfserr_cb_path_down;
        if (!list_empty(&clp->cl_delegations)
-                       && !atomic_read(&clp->cl_cb_conn.cb_set))
+                       && !atomic_read(&clp->cl_cb_set))
                goto out;
        status = nfs_ok;
 out: