Re: [PATCH net-next 1/5] tls: reject the combination of TLS and sockmap

[Jakub Sitnicki <jakub@cloudflare.com>]

On Sun, Jun 14, 2026 at 10:09 AM +02, Paolo Abeni wrote:
> On 6/14/26 3:40 AM, Jakub Kicinski wrote:
>> TLS and sockmap (BPF psock) integration hides a lot of latent bugs.
>> Bugs which may be more or less relevant for real users but they
>> are definitely exploitable.
>> 
>> We could not find anyone actively using this integration so let's
>> reject this config. Adding a TLS socket to a sockmap was already
>> rejected by sk_psock_init() through the inet_csk_has_ulp() check.
>> We need to reject the attempts to configure the TLS keys (rather
>> than adding the ULP itself) because checking prior to the ULP
>> installation is tricky without risking a race with sockmap getting
>> added in parallel (sockmap does not hold the socket lock).
>
> Aren't both tls_ctx_create() and sk_psock_init() under (write) the
> callback lock? Isn't that enough to avoid races?

+1, but we would have to tweak inet_csk_has_ulp() to check for
icsk_ulp_data in addition to icsk_ulp_ops. Only icsk_ulp_data is set
under sk_callback_lock.

espintcp faces the same race...