Re: [PATCH] tcp: fix race condition when creating child sockets from syncookies

[Eric Dumazet]

On Fri, Oct 23, 2020 at 1:14 PM Ricardo Dias <rdias@xxxxxxxxxx> wrote:
>
> When the TCP stack is in SYN flood mode, the server child socket is
> created from the SYN cookie received in a TCP packet with the ACK flag
> set.
>
...

This patch only handles IPv4, unless I am missing something ?

It looks like the fix should be done in inet_ehash_insert(), not
adding yet another helper in TCP.
This would be family generic.

Note that normally, all packets for the same 4-tuple should be handled
by the same cpu,
so this race is quite unlikely to happen in standard setups.