NFS: Fix infinite loop in gss_create_upcall()

There can be an infinite loop if gss_create_upcall() is called without
the userspace program running.  To prevent this, we return -EACCES if
we notice that pipe_version hasn't changed (indicating that the pipe
has not been opened).

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 9bf41eab3e46..8a03ee0689f3 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2224,8 +2224,9 @@ static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
 
         for (i = 0; i < len; i++) {
                 status = nfs4_lookup_root_sec(server, fhandle, info, flav_array[i]);
-                if (status != -EPERM)
-                        break;
+                if (status == -EPERM || status == -EACCES)
+                        continue;
+                break;
         }
         if (status == 0)
                 status = nfs4_server_capabilities(server, fhandle);