netdev - Re: [RFC -next 1/2] lib: add reference counting infrastructure

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: <CANn89iLnk+cfKcBk-6oQhiKDYg=mYaYrp-S=k0M5WJCkgHm+bw@mail.gmail.com>
Date:   Tue, 30 Nov 2021 07:07:50 -0800
From:   Eric Dumazet <edumazet@...gle.com>
To:     Dmitry Vyukov <dvyukov@...gle.com>
Cc:     eric.dumazet@...il.com, davem@...emloft.net, kuba@...nel.org,
        netdev@...r.kernel.org
Subject: Re: [RFC -next 1/2] lib: add reference counting infrastructure

On Tue, Nov 30, 2021 at 1:09 AM Dmitry Vyukov <dvyukov@...gle.com> wrote:
>
> Hi Eric, Jakub,
>
> How strongly do you want to make this work w/o KASAN?
> I am asking because KASAN will already memorize alloc/free stacks for every
> heap object (+ pids + 2 aux stacks with kasan_record_aux_stack()).
> So basically we just need to alloc struct list_head and won't need
> quarantine/quarantine_avail in ref_tracker_dir.
> If there are some refcount bugs, it may be due to a previous use-after-free,
> so debugging a refcount bug w/o KASAN may be waste of time.
>

No strong opinion, we could have the quarantine stuff enabled only if
KASAN is not compiled in.
I was trying to make something that could be used even in a production
environment, for seldom modified refcounts.
As this tracking is optional, we do not have to use it in very small
sections of code, where the inc/dec are happening in obviously correct
and not long living pairs.