nfs: reject changes to resvport and sharecache during remount
Commit c8e47028 made it possible to change resvport/noresvport and
sharecache/nosharecache via a remount operation, neither of which should be
allowed.
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Fixes: c8e47028 (nfs: Apply NFS_MOUNT_CMP_FLAGMASK to nfs_compare_remount_data)
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index c08e837..e4499d5 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2179,7 +2179,7 @@
return -EINVAL;
}
-#define NFS_MOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
+#define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
| NFS_MOUNT_SECURE \
| NFS_MOUNT_TCP \
| NFS_MOUNT_VER3 \
@@ -2187,15 +2187,16 @@
| NFS_MOUNT_NONLM \
| NFS_MOUNT_BROKEN_SUID \
| NFS_MOUNT_STRICTLOCK \
- | NFS_MOUNT_UNSHARED \
- | NFS_MOUNT_NORESVPORT \
| NFS_MOUNT_LEGACY_INTERFACE)
+#define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
+ ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
+
static int
nfs_compare_remount_data(struct nfs_server *nfss,
struct nfs_parsed_mount_data *data)
{
- if ((data->flags ^ nfss->flags) & NFS_MOUNT_CMP_FLAGMASK ||
+ if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
data->rsize != nfss->rsize ||
data->wsize != nfss->wsize ||
data->version != nfss->nfs_client->rpc_ops->version ||