Re: [PATCH net] tcp: fix forever orphan socket caused by tcp_abort

[Lorenzo Colitti]

On Mon, Aug 5, 2024 at 4:23 PM Eric Dumazet <edumazet@xxxxxxxxxx> wrote:
> > Each time we call inet_csk_destroy_sock(), we must make sure we've
> > already set the state to TCP_CLOSE. Based on this, I think we can use
> > this as an indicator to avoid calling twice to destroy the socket.
>
> I do not think this will work.
>
> With this patch, a listener socket will not get an error notification.
>
> Ideally we need tests for this seldom used feature.

FWIW there is a fair amount of test coverage here:

https://cs.android.com/android/platform/superproject/main/+/main:kernel/tests/net/test/sock_diag_test.py

though unfortunately they don't pass on unmodified kernels (I didn't
look into why - maybe Maciej knows). I ran the tests on the "v2-ish
patch" and they all passed except for a test that expects that
SOCK_DESTROY on a FIN_WAIT1 socket does nothing. That seems OK because
it's the thing your patch is trying to fix.

Just to confirm - it's OK to send a RST on a connection that's already
in FIN_WAIT1 state? Is that allowed by the RFC?