Re: [PATCH v2 2/2] net: return early for possible invalid uaddr

From: Eric Dumazet
Date: Wed Aug 11 2021 - 12:12:02 EST




On 8/11/21 5:24 PM, Wen Yang wrote:
> The inet_dgram_connect() first calls inet_autobind() to select an
> ephemeral port, then checks uaddr in udp_pre_connect() or
> __ip4_datagram_connect(), but the port is not released until the socket
> is closed. This could cause performance issues or even exhaust ephemeral
> ports if a malicious user makes a large number of UDP connections with
> invalid uaddr and/or addr_len.
>
>

This is a big patch.

Can the malicious user still use a large number of UDP sockets,
with valid uaddr/add_len and consequently exhaust ephemeral ports ?

If yes, it does not seem your patch is helping.

If no, have you tried instead to undo the autobind, if the connect fails ?