| Date | Tue, 23 Oct 2018 17:22:03 +0100 | From | Al Viro <> | Subject | Re: [PATCH 03/34] teach move_mount(2) to work with OPEN_TREE_CLONE [ver #12] |
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On Tue, Oct 23, 2018 at 12:19:35PM +0100, Alan Jenkins wrote:
> I think there's another small hole. It is possible to move a sub-mount from > a detached tree (instead of moving the root of the tree). Then > do_move_mount() calls attach_recursive_mnt() with a non-NULL parent_path. > > This causes it to skip count_mounts(). So, it doesn't count the number of > attached mounts, and it allows you to exceed sysctl_mount_max.
That's trivial to repair, fortunately - we just need to check source_mnt->mnt_ns instead of parent_path.
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