From mboxrd@z Thu Jan 1 00:00:00 1970 From: Valerie Aurora Subject: [PATCH 24/34] union-mount: Prevent bind mounts of union mounts Date: Thu, 16 Sep 2010 15:12:15 -0700 Message-ID: <1284675145-4391-25-git-send-email-vaurora@redhat.com> References: <1284675145-4391-1-git-send-email-vaurora@redhat.com> Cc: Miklos Szeredi , Christoph Hellwig , Andreas Gruenbacher , Nick Piggin , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Valerie Aurora To: Alexander Viro Return-path: In-Reply-To: <1284675145-4391-1-git-send-email-vaurora@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Prevent bind mounts of parts of union mounts. XXX - Bind mounting parts of union mounts is probably easy to implement, but requires some careful thought about corner cases, extensive testing, and some refactoring of the code. Signed-off-by: Valerie Aurora --- fs/namespace.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 26efaf3..e3629dd 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1761,6 +1761,12 @@ static int do_loopback(struct path *path, char *old_name, err = -EINVAL; if (IS_MNT_UNBINDABLE(old_path.mnt)) goto out; + /* + * XXX - Mounting a subtree of a union mount elsewhere + * requires careful thought and some refactoring. + */ + if (IS_MNT_UNION(old_path.mnt)) + goto out; if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt)) goto out; -- 1.6.3.3