NFSv4: Disallow security negotiation for lookups when 'sec=' is specified

Ensure that nfs4_proc_lookup_common respects the NFS_MOUNT_SECFLAVOUR
flag.

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

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 68551ea0b673..122b9340e6ef 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3154,7 +3154,9 @@ static int nfs4_proc_lookup_common(struct rpc_clnt **clnt, struct inode *dir,
                         err = -EPERM;
                         if (client != *clnt)
                                 goto out;
-
+                        /* No security negotiation if the user specified 'sec=' */
+                        if (NFS_SERVER(dir)->flags & NFS_MOUNT_SECFLAVOUR)
+                                goto out;
                         client = nfs4_create_sec_client(client, dir, name);
                         if (IS_ERR(client))
                                 return PTR_ERR(client);