Messages in this thread Patch in this message | | | From | Dmitry Safonov <> | Subject | [PATCH v4 5/7] net/tcp: Don't add key with non-matching VRF on connected sockets | Date | Wed, 29 Nov 2023 16:57:19 +0000 |
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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 shooting itself somewhere.
Yet, nothing restricts the CAP_NET_RAW user from trying to shoot themselves by performing setsockopt(SO_BINDTODEVICE) or setsockopt(SO_BINDTOIFINDEX) over an established TCP-AO connection. So, this is just "minimum effort" to potentially save someone's debugging time, rather than a full restriction on doing weird things.
Fixes: 248411b8cb89 ("net/tcp: Wire up l3index to TCP-AO") Signed-off-by: Dmitry Safonov <dima@arista.com> --- net/ipv4/tcp_ao.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c index bf41be6d4721..465c871786aa 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -1608,6 +1608,15 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family, if (!dev || !l3index) return -EINVAL; + if (!bound_dev_if || bound_dev_if != cmd.ifindex) { + /* tcp_ao_established_key() doesn't expect having + * non peer-matching key on an established TCP-AO + * connection. + */ + if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))) + return -EINVAL; + } + /* 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 -- 2.43.0
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