netdev - Re: rtnl_trylock() versus SCHED

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>] [day] [month] [year] [list]

Message-ID: <20200809083233.00822e44@hermes.lan>
Date:   Sun, 9 Aug 2020 08:32:33 -0700
From:   Stephen Hemminger <stephen@...workplumber.org>
To:     Hillf Danton <hdanton@...a.com>
Cc:     Rasmus Villemoes <rasmus.villemoes@...vas.dk>,
        Nikolay Aleksandrov <nikolay@...ulusnetworks.com>,
        Network Development <netdev@...r.kernel.org>,
        Markus Elfring <Markus.Elfring@....de>
Subject: Re: rtnl_trylock() versus SCHED_FIFO lockup

On Sun,  9 Aug 2020 21:49:24 +0800
Hillf Danton <hdanton@...a.com> wrote:

> +
> +static void br_workfn(struct work_struct *w)
> +{
> +	struct br_work *brw = container_of(w, struct br_work, work);
> +
> +	rtnl_lock();
> +	brw->err = brw->set(brw->br, brw->val);
> +	if (!brw->err)
> +		netdev_state_change(brw->br->dev);
> +	rtnl_unlock();
> +
> +	brw->done = true;
> +	wake_up(&brw->waitq);
> +}

Sorry, this is unsafe.
This has the potential of running when bridge itself has been
deleted.