Re: [PATCH bpf-next] net: Fix slab-out-of-bounds in inet[6]_steal_sock

[Lorenz Bauer]

On Wed, Aug 9, 2023 at 4:56 PM Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> wrote:
>
> > Things we could do if necessary:
> > 1. Reset the flag in inet_csk_clone_lock like we do for SOCK_RCU_FREE
>
> I think we can't do this as sk_reuseport is inherited to twsk and used
> in inet_bind_conflict().

Ok, so what kind of state does reuseport carry in the various states then?

TCP_LISTEN: sk_reuseport && sk_reuseport_cb
TCP_ESTABLISHED: sk_reuseport && !sk_reuseport_cb
TCP_TIME_WAIT: sk_reuseport && !sk_reuseport_cb

Where is sk_reuseport_cb cleared? On clone? Or not at all?

> > 2. Duplicate the cb check into inet[6]_steal_sock
>
> or 3. Add sk_fullsock() test ?

I guess this would be in addition to the convoluted series of checks
I've removed in this patch?