On Mon, 27 Nov 2023 10:33:45 +1100 David Gibson <david(a)gibson.dropbear.id.au> wrote:In tcp_timer_handler() we use conn_at_idx() to interpret the flow index from the epoll reference. However, this will never be NULL - we always put a valid index into the epoll_ref. Simplify slightly based on this.Sorry, I missed this during review of v1. I have mixed feeling about this, and I don't think 11/11 changes anything in this regard: we have to trust the kernel, as there's no benefit to security in not doing so. At the same time, should we ever get an out-of-bounds index from the epoll event, we can fail gracefully here. Slightly worse, however: if we get a timer event for a connection that's already closed, we'll happily go and try to manipulate its timer (with or without the !conn check). All in all, I think the check is minimally useful, and we should have something more robust than that. So if this patch helps keeping things simple later in the series, I don't see an issue with that, but perhaps we should add back a more sensible set of checks later. The next patches all look good to me. -- Stefano