netdev - Re: [PATCH v2 1/2] netlink: add NLA

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180918.195142.1871581637054906657.davem@redhat.com>
Date:   Tue, 18 Sep 2018 19:51:42 -0700 (PDT)
From:   David Miller <davem@...hat.com>
To:     johannes@...solutions.net
Cc:     netdev@...r.kernel.org, marcelo.leitner@...il.com,
        mkubecek@...e.cz, johannes.berg@...el.com
Subject: Re: [PATCH v2 1/2] netlink: add NLA_REJECT policy type

From: Johannes Berg <johannes@...solutions.net>
Date: Mon, 17 Sep 2018 11:57:28 +0200

> From: Johannes Berg <johannes.berg@...el.com>
> 
> In some situations some netlink attributes may be used for output
> only (kernel->userspace) or may be reserved for future use. It's
> then helpful to be able to prevent userspace from using them in
> messages sent to the kernel, since they'd otherwise be ignored and
> any future will become impossible if this happens.
> 
> Add NLA_REJECT to the policy which does nothing but reject (with
> EINVAL) validation of any messages containing this attribute.
> Allow for returning a specific extended ACK error message in the
> validation_data pointer.
> 
> While at it clear up the documentation a bit - the NLA_BITFIELD32
> documentation was added to the list of len field descriptions.
> 
> Also, use NL_SET_BAD_ATTR() in one place where it's open-coded.
> 
> The specific case I have in mind now is a shared nested attribute
> containing request/response data, and it would be pointless and
> potentially confusing to have userspace include response data in
> the messages that actually contain a request.
> 
> Signed-off-by: Johannes Berg <johannes.berg@...el.com>
> ---
> v2: preserve behaviour of overwriting the extack message, with
>     either the generic or the specific one now

Applied.