mnt: Carefully set CL_UNPRIVILEGED in clone_mnt

old->mnt_expiry should be ignored unless CL_EXPIRE is set.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

diff --git a/fs/namespace.c b/fs/namespace.c
index e8d1ffa..f87a90b 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -963,7 +963,8 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root,
        }
 
        /* Don't allow unprivileged users to reveal what is under a mount */
-       if ((flag & CL_UNPRIVILEGED) && list_empty(&old->mnt_expire))
+       if ((flag & CL_UNPRIVILEGED) &&
+           (!(flag & CL_EXPIRE) || list_empty(&old->mnt_expire)))
                mnt->mnt.mnt_flags |= MNT_LOCKED;
 
        atomic_inc(&sb->s_active);