netdev - Re: [PATCH net-next v2 3/3] netlink: add validation of NLA_F

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]

Date:   Tue, 23 Jul 2019 20:17:47 +0200
From:   Johannes Berg <johannes@...solutions.net>
To:     Stephen Hemminger <stephen@...workplumber.org>,
        Michal Kubecek <mkubecek@...e.cz>
Cc:     "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
        David Ahern <dsahern@...il.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH net-next v2 3/3] netlink: add validation of NLA_F_NESTED
 flag

On Tue, 2019-07-23 at 11:02 -0700, Stephen Hemminger wrote:
> 
> There are some cases where netlink related to IPv4 does not send nested
> flag. You risk breaking older iproute2 and other tools being used on newer
> kernel. I.e this patch may break binary compatibility. Have you tried running
> with this on a very old distro (like Redhat Linux 9)?


There are *tons* of places where this (and other things) wasn't done
right, but the validation is only added for

 * all attributes on _new operations_ (that old userspace couldn't have
   been using since they're introduced after this patch)
 * _new attributes_ (dito, if the policy 'strict start' is filled)

johannes