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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu, 12 Jul 2018 13:36:22 -0700
Message-ID: <CA+55aFx=tVoeyDWqeNtv-v=r_v7pwbTV+KCrzg4Mzab66MuxEA@mail.gmail.com>
Subject: Re: [PATCH 24/32] vfs: syscall: Add fsopen() to prepare for
 superblock creation [ver #9]
To:     David Howells <dhowells@redhat.com>
Cc:     Andrew Lutomirski <luto@kernel.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Linux API <linux-api@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Jann Horn <jannh@google.com>
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On Thu, Jul 12, 2018 at 1:34 PM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> This is the whole "write() is only for data". If you ever have
> credentials mattering at write time, you're doing something wrong.
>
> Really really.
>
> Don't do it.

.. and I'd like to repeat: we *have* done things wrong. But that's
simply not an excuse. We've done it wrong in SCSI, we've done it wrong
in various /proc files, we've done it wrong in many places.

But let's not do it wrong AGAIN.

                Linus