[PATCH v2 2/2] vhost: fix possible FD leaks on MSG_TRUNC and MSG_CTRUNC

[David Marchand]

On Fri, Jan 27, 2023 at 5:55 PM Maxime Coquelin
<maxime.coquelin at redhat.com> wrote:
>
> This patch fixes possible FDs leaks when truncation happens
> on either the message buffer or its control data. Indeed,
> by returning early, it did not let a chance to retrieve the
> FDs passed as ancillary data, and so caused a potential FDs
> leak.
>
> This patch fixes this by extracting the FDs from the
> ancillary data as long as recvmsg() call succeeded. It also
> improves the logs to differentiate between MSG_TRUNC and
> MSG_CTRUNC.

As I mentionned offlist, I am not convinced the MSG_TRUNC flag can be
set on receipt of a message, since the socket is in stream mode.
I am okay to keep the check as is, but it is confusing.


>
> Fixes: bf472259dde6 ("vhost: fix possible denial of service by leaking FDs")
> Cc: stable at dpdk.org
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>

Reviewed-by: David Marchand <david.marchand at redhat.com>


-- 
David Marchand