NFSv4: Disallow 'mount -t nfs4 -overs=2' and 'mount -t nfs4 -overs=3'

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

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 34b1ccf51adf..867f70504531 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2321,6 +2321,12 @@ static int nfs4_validate_text_mount_data(void *options,
 
         nfs4_validate_mount_flags(args);
 
+        if (args->version != 4) {
+                dfprintk(MOUNT,
+                         "NFS4: Illegal mount version\n");
+                return -EINVAL;
+        }
+
         if (args->auth_flavor_len > 1) {
                 dfprintk(MOUNT,
                          "NFS4: Too many RPC auth flavours specified\n");