fs: relax mount_setattr() permission checks

[linux-2.6-microblaze.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 437f60e..5a51315 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -4472,10 +4472,15 @@ static int do_mount_setattr(struct path *path, struct mount_kattr *kattr)
        /*
         * If this is an attached mount make sure it's located in the callers
         * mount namespace. If it's not don't let the caller interact with it.
-        * If this is a detached mount make sure it has an anonymous mount
-        * namespace attached to it, i.e. we've created it via OPEN_TREE_CLONE.
+        *
+        * If this mount doesn't have a parent it's most often simply a
+        * detached mount with an anonymous mount namespace. IOW, something
+        * that's simply not attached yet. But there are apparently also users
+        * that do change mount properties on the rootfs itself. That obviously
+        * neither has a parent nor is it a detached mount so we cannot
+        * unconditionally check for detached mounts.
         */
-       if (!(mnt_has_parent(mnt) ? check_mnt(mnt) : is_anon_ns(mnt->mnt_ns)))
+       if ((mnt_has_parent(mnt) || !is_anon_ns(mnt->mnt_ns)) && !check_mnt(mnt))
                goto out;
 
        /*