linux-kernel - Re: [PATCH] block: revert pushing the final release of request

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:   Sun, 9 Feb 2020 17:00:38 -0800
From:   Bart Van Assche <bvanassche@....org>
To:     yu kuai <yukuai3@...wei.com>, axboe@...nel.dk, ming.lei@...hat.com,
        chaitanya.kulkarni@....com, damien.lemoal@....com,
        dhowells@...hat.com, asml.silence@...il.com, ajay.joshi@....com
Cc:     linux-block@...r.kernel.org, linux-kernel@...r.kernel.org,
        yi.zhang@...wei.com, zhangxiaoxu5@...wei.com,
        luoshijie1@...wei.com, jan kara <jack@...e.cz>
Subject: Re: [PATCH] block: revert pushing the final release of request_queue
 to a workqueue.

On 2020-02-06 03:10, yu kuai wrote:
> syzbot is reporting use after free bug in debugfs_remove[1].
> 
> This is because in request_queue, 'q->debugfs_dir' and
> 'q->blk_trace->dir' could be the same dir. And in __blk_release_queue(),
> blk_mq_debugfs_unregister() will remove everything inside the dir.

Hi Yu,

Have you already noticed patch "[PATCH] blktrace: Protect q->blk_trace
with RCU"? If not, have you already tried to verify whether that patch
fixes the use-after-free detected by syzbot? See also
https://lore.kernel.org/linux-block/BYAPR04MB57492F689BA17786A24F08EE86190@BYAPR04MB5749.namprd04.prod.outlook.com/T/#mce8ffe534d93716f678d52178b4e34d4d1c3c597

Thanks,

Bart.