Re: [PATCH] libbpf: Fix integer overflow issue

From: Andrii Nakryiko
Date: Tue Oct 08 2024 - 13:22:31 EST


On Tue, Oct 8, 2024 at 2:49 AM Eduard Zingerman <eddyz87@xxxxxxxxx> wrote:
>
> On Mon, 2024-10-07 at 20:42 -0700, Andrii Nakryiko wrote:
>
> [...]
>
> > Not sure what Eduard is suggesting here, tbh. But I think if this
> > actually can happen that we have a non-loaded BPF program in one of
> > those struct_ops slots, then let's add a test demonstrating that.
>
> Given the call chain listed in a previous email I think that such
> situation is not possible (modulo obj->gen_loader, which I know
> nothing about).
>
> Thus I suggest to add a pr_warn() and return -EINVAL or something like
> that here.
>

That's what confused me :) If it's impossible, there is no need to
handle it, we know the FD has to be there. So I'd just not change
anything.

> > Worst case of what can happen right now is the kernel rejecting
> > struct_ops loading due to -22 as a program FD.
> >
> > pw-bot: cr
>
> [...]
>