linux-kernel - Re: [PATCH] nvme-tcp: Check if request has started before processing it

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: <ddf87227-1ad3-b8be-23ba-460433f70a85@grimberg.me>
Date:   Fri, 12 Feb 2021 13:49:32 -0800
From:   Sagi Grimberg <sagi@...mberg.me>
To:     Keith Busch <kbusch@...nel.org>
Cc:     Daniel Wagner <dwagner@...e.de>, linux-nvme@...ts.infradead.org,
        linux-kernel@...r.kernel.org, Christoph Hellwig <hch@....de>,
        Jens Axboe <axboe@...com>, Hannes Reinecke <hare@...e.de>
Subject: Re: [PATCH] nvme-tcp: Check if request has started before processing
 it


>>> blk_mq_tag_to_rq() will always return a request if the command_id is
>>> in the valid range. Check if the request has been started. If we
>>> blindly process the request we might double complete a request which
>>> can be fatal.
>>
>> How did you get to this one? did the controller send a completion for
>> a completed/bogus request?
> 
> If that is the case, then that must mean it's possible the driver could
> have started the command id just before the bogus completion check. Data
> iorruption, right?

Yes, which is why I don't think this check is very useful..