Re: [PATCH v3 5/7] net/tcp: Don't add key with non-matching VRF on connected sockets

From: David Ahern
Date: Tue Nov 28 2023 - 20:35:05 EST


On 11/28/23 1:57 PM, Dmitry Safonov wrote:
> If the connection was established, don't allow adding TCP-AO keys that
> don't match the peer. Currently, there are checks for ip-address
> matching, but L3 index check is missing. Add it to restrict userspace

you say L3 index check is missing - add it. yet ...

> shooting itself somewhere.
>
> Fixes: 248411b8cb89 ("net/tcp: Wire up l3index to TCP-AO")
> Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
> ---
> net/ipv4/tcp_ao.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
> index bf41be6d4721..2d000e275ce7 100644
> --- a/net/ipv4/tcp_ao.c
> +++ b/net/ipv4/tcp_ao.c
> @@ -1608,6 +1608,9 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
> if (!dev || !l3index)
> return -EINVAL;
>
> + if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)))
> + return -EINVAL;

... this is checking socket state.


> +
> /* It's still possible to bind after adding keys or even
> * re-bind to a different dev (with CAP_NET_RAW).
> * So, no reason to return error here, rather try to be