linux-kernel - Re: [PATCH V3] mISDN: fix use-after-free bugs in l1oip timer handlers

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: <20220927172618.58f238d6@kernel.org>
Date:   Tue, 27 Sep 2022 17:26:18 -0700
From:   Jakub Kicinski <kuba@...nel.org>
To:     Duoming Zhou <duoming@....edu.cn>
Cc:     linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
        isdn@...ux-pingi.de
Subject: Re: [PATCH V3] mISDN: fix use-after-free bugs in l1oip timer
 handlers

On Sat, 24 Sep 2022 10:18:42 +0800 Duoming Zhou wrote:
> +	del_timer_sync(&hc->keep_tl);
> +	del_timer_sync(&hc->timeout_tl);
> +	cancel_work_sync(&hc->workq);
> +	del_timer_sync(&hc->keep_tl);
>  	cancel_work_sync(&hc->workq);

Why not add a bit which will indicate that the device is shutting 
down and check it in places which schedule the timer?
I think that's much easier to reason about and we won't need to do 
this rep cancel procedure.