Re: [RFC v6 03/40] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD permission flags

From: Andy Lutomirski
Date: Fri Aug 28 2015 - 17:37:00 EST


On Tue, Aug 4, 2015 at 4:53 AM, Andreas Gruenbacher
<andreas.gruenbacher@xxxxxxxxx> wrote:
> Normally, deleting a file requires write and execute access to the parent
> directory. With Richacls, a process with MAY_DELETE_SELF access to a file
> may delete the file even without write access to the parent directory.
>
> To support that, pass the MAY_DELETE_CHILD mask flag to inode_permission()
> when checking for delete access inside a directory, and MAY_DELETE_SELF
> when checking for delete access to a file itelf.
>
> The MAY_DELETE_SELF permission does not override the sticky directory
> check. It probably should.

Silly question from the peanut gallery: is there any such thing as
opening an fd pointing at a file such that the "open file description"
(i.e. the struct file) captures the right to delete the file?

IOW do we need FMODE_DELETE_SELF?

--Andy
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