linux-kernel - Re: [PATCH] block: do not put mq context in blk_mq_alloc_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] [day] [month] [year] [list]

Message-ID: <8787097b-7da5-3ae7-7896-cd08f5376018@fb.com>
Date:   Thu, 30 Mar 2017 08:12:28 -0600
From:   Jens Axboe <axboe@...com>
To:     Minchan Kim <minchan@...nel.org>
CC:     <kernel-team@....com>, <linux-block@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, Sagi Grimberg <sagi@...mberg.me>,
        "Omar Sandoval" <osandov@...com>
Subject: Re: [PATCH] block: do not put mq context in blk_mq_alloc_request_hctx

On 03/29/2017 11:20 PM, Minchan Kim wrote:
> In blk_mq_alloc_request_hctx, blk_mq_sched_get_request doesn't
> get sw context so we don't need to put the context with
> blk_mq_put_ctx. Unless, we will see preempt counter underflow.

Good catch, that's definitely a bug. I have applied your patch
for 4.11.

-- 
Jens Axboe