Merge tag 'nfs-for-3.14-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include stable fixes for the following bugs:

   - General performance regression due to NFS_INO_INVALID_LABEL being
     set when the server doesn't support labeled NFS
   - Hang in the RPC code due to a socket out-of-buffer race
   - Infinite loop when trying to establish the NFSv4 lease
   - Use-after-free bug in the RPCSEC gss code.
   - nfs4_select_rw_stateid is returning with a non-zero error value on
     success

  Other bug fixes:

  - Potential memory scribble in the RPC bi-directional RPC code
  - Pipe version reference leak
  - Use the correct net namespace in the new NFSv4 migration code"

* tag 'nfs-for-3.14-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS fix error return in nfs4_select_rw_stateid
  NFSv4: Use the correct net namespace in nfs4_update_server
  SUNRPC: Fix a pipe_version reference leak
  SUNRPC: Ensure that gss_auth isn't freed before its upcall messages
  SUNRPC: Fix potential memory scribble in xprt_free_bc_request()
  SUNRPC: Fix races in xs_nospace()
  SUNRPC: Don't create a gss auth cache unless rpc.gssd is running
  NFS: Do not set NFS_INO_INVALID_LABEL unless server supports labeled NFS

3 files changed, 25 insertions, 6 deletions

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 6c0513a7f992..36e431ee1c90 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -108,6 +108,7 @@ struct gss_auth {
 static DEFINE_SPINLOCK(pipe_version_lock);
 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
+static void gss_put_auth(struct gss_auth *gss_auth);
 
 static void gss_free_ctx(struct gss_cl_ctx *);
 static const struct rpc_pipe_ops gss_upcall_ops_v0;
@@ -320,6 +321,7 @@ gss_release_msg(struct gss_upcall_msg *gss_msg)
         if (gss_msg->ctx != NULL)
                 gss_put_ctx(gss_msg->ctx);
         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
+        gss_put_auth(gss_msg->auth);
         kfree(gss_msg);
 }
 
@@ -498,9 +500,12 @@ gss_alloc_msg(struct gss_auth *gss_auth,
         default:
                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
                 if (err)
-                        goto err_free_msg;
+                        goto err_put_pipe_version;
         };
+        kref_get(&gss_auth->kref);
         return gss_msg;
+err_put_pipe_version:
+        put_pipe_version(gss_auth->net);
 err_free_msg:
         kfree(gss_msg);
 err:
@@ -991,6 +996,8 @@ gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
         if (gss_auth->service == 0)
                 goto err_put_mech;
+        if (!gssd_running(gss_auth->net))
+                goto err_put_mech;
         auth = &gss_auth->rpc_auth;
         auth->au_cslack = GSS_CRED_SLACK >> 2;
         auth->au_rslack = GSS_VERF_SLACK >> 2;
@@ -1062,6 +1069,12 @@ gss_free_callback(struct kref *kref)
 }
 
 static void
+gss_put_auth(struct gss_auth *gss_auth)
+{
+        kref_put(&gss_auth->kref, gss_free_callback);
+}
+
+static void
 gss_destroy(struct rpc_auth *auth)
 {
         struct gss_auth *gss_auth = container_of(auth,
@@ -1082,7 +1095,7 @@ gss_destroy(struct rpc_auth *auth)
         gss_auth->gss_pipe[1] = NULL;
         rpcauth_destroy_credcache(auth);
 
-        kref_put(&gss_auth->kref, gss_free_callback);
+        gss_put_auth(gss_auth);
 }
 
 /*
@@ -1253,7 +1266,7 @@ gss_destroy_nullcred(struct rpc_cred *cred)
         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
         if (ctx)
                 gss_put_ctx(ctx);
-        kref_put(&gss_auth->kref, gss_free_callback);
+        gss_put_auth(gss_auth);
 }
 
 static void
diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index 890a29912d5a..e860d4f7ed2a 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -64,7 +64,6 @@ static void xprt_free_allocation(struct rpc_rqst *req)
         free_page((unsigned long)xbufp->head[0].iov_base);
         xbufp = &req->rq_snd_buf;
         free_page((unsigned long)xbufp->head[0].iov_base);
-        list_del(&req->rq_bc_pa_list);
         kfree(req);
 }
 
@@ -168,8 +167,10 @@ out_free:
         /*
          * Memory allocation failed, free the temporary list
          */
-        list_for_each_entry_safe(req, tmp, &tmp_list, rq_bc_pa_list)
+        list_for_each_entry_safe(req, tmp, &tmp_list, rq_bc_pa_list) {
+                list_del(&req->rq_bc_pa_list);
                 xprt_free_allocation(req);
+        }
 
         dprintk("RPC:       setup backchannel transport failed\n");
         return -ENOMEM;
@@ -198,6 +199,7 @@ void xprt_destroy_backchannel(struct rpc_xprt *xprt, unsigned int max_reqs)
         xprt_dec_alloc_count(xprt, max_reqs);
         list_for_each_entry_safe(req, tmp, &xprt->bc_pa_list, rq_bc_pa_list) {
                 dprintk("RPC:        req=%p\n", req);
+                list_del(&req->rq_bc_pa_list);
                 xprt_free_allocation(req);
                 if (--max_reqs == 0)
                         break;
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 817a1e523969..0addefca8e77 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -510,6 +510,7 @@ static int xs_nospace(struct rpc_task *task)
         struct rpc_rqst *req = task->tk_rqstp;
         struct rpc_xprt *xprt = req->rq_xprt;
         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
+        struct sock *sk = transport->inet;
         int ret = -EAGAIN;
 
         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
@@ -527,7 +528,7 @@ static int xs_nospace(struct rpc_task *task)
                          * window size
                          */
                         set_bit(SOCK_NOSPACE, &transport->sock->flags);
-                        transport->inet->sk_write_pending++;
+                        sk->sk_write_pending++;
                         /* ...and wait for more buffer space */
                         xprt_wait_for_buffer_space(task, xs_nospace_callback);
                 }
@@ -537,6 +538,9 @@ static int xs_nospace(struct rpc_task *task)
         }
 
         spin_unlock_bh(&xprt->transport_lock);
+
+        /* Race breaker in case memory is freed before above code is called */
+        sk->sk_write_space(sk);
         return ret;
 }