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Date:   Thu, 1 Apr 2021 13:33:00 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Yongji Xie <xieyongji@bytedance.com>
Cc:     devel@driverdev.osuosl.org, tkjos@android.com,
        Kees Cook <keescook@chromium.org>,
        Suren Baghdasaryan <surenb@google.com>,
        Jason Wang <jasowang@redhat.com>,
        Sargun Dhillon <sargun@sargun.me>,
        Christoph Hellwig <hch@infradead.org>,
        Hridya Valsaraju <hridya@google.com>, arve@android.com,
        viro@zeniv.linux.org.uk, joel@joelfernandes.org,
        linux-fsdevel@vger.kernel.org,
        Christian Brauner <christian.brauner@ubuntu.com>,
        maco@android.com
Subject: Re: Re: Re: [PATCH 2/2] binder: Use receive_fd() to receive file
 from another process
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On Thu, Apr 01, 2021 at 07:29:45PM +0800, Yongji Xie wrote:
> On Thu, Apr 1, 2021 at 6:42 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Thu, Apr 01, 2021 at 06:12:51PM +0800, Yongji Xie wrote:
> > > On Thu, Apr 1, 2021 at 5:54 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> > > >
> > > > On Thu, Apr 01, 2021 at 05:09:32PM +0800, Xie Yongji wrote:
> > > > > Use receive_fd() to receive file from another process instead of
> > > > > combination of get_unused_fd_flags() and fd_install(). This simplifies
> > > > > the logic and also makes sure we don't miss any security stuff.
> > > >
> > > > But no logic is simplified here, and nothing is "missed", so I do not
> > > > understand this change at all.
> > > >
> > >
> > > I noticed that we have security_binder_transfer_file() when we
> > > transfer some fds. I'm not sure whether we need something like
> > > security_file_receive() here?
> >
> > Why would you?  And where is "here"?
> >
> > still confused,
> >
> 
> I mean do we need to go through the file_receive seccomp notifier when
> we receive fd (use get_unused_fd_flags() + fd_install now) from
> another process in binder_apply_fd_fixups().

Why?  this is internal things, why does seccomp come into play here?