Re: [PATCH 0/3] vmsplice: make vmsplice a trivial wrapper for preadv2/pwritev2

[Christian Brauner]

On Tue, Jun 02, 2026 at 09:20:13PM -0700, Linus Torvalds wrote:
> On Tue, 2 Jun 2026 at 20:51, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
> >
> > Am I understanding correctly that this will completely break zerocopy
> > sendfile?
> 
> Very much, yes.
> 
> And it's worth making it very very clear that ABSOLUTELY NONE of the
> recent big security bugs were in splice.
> 
> They were all in the networking and crypto code that just didn't deal
> with shared data correctly.
> 
> So in that sense, it's a bit sad to discuss castrating splice.

Well, we're completely ignoring the fact that splice()'s locking and
interactions with pipe_lock() are complete insanity. So unless someone
sits down and really thinks about how to rework the locking I think
degrading splice() is just fine.

> But it's probably still the right thing to at least try.

Yes.

> I just suspect we'll never get real answers without going the "let's
> just see what happens" route...

Yes.