linux-kernel - Re: [PATCH] cgroup: Improve cgroup_addrm

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: <be07fa50-12ce-4fb9-b2f4-445eaab220fa@bytedance.com>
Date: Wed, 12 Nov 2025 10:41:41 +0800
From: Wenyu Liu <liuwenyu.0311@...edance.com>
To: Michal Koutný <mkoutny@...e.com>
Cc: tj@...nel.org, hannes@...xchg.org, cgroups@...r.kernel.org,
 linux-kernel@...r.kernel.org, Wenyu Liu <liuwenyu.0311@...edance.com>
Subject: Re: [PATCH] cgroup: Improve cgroup_addrm_files remove files handling

在 11/11/25 21:54, Michal Koutný 写道:
> Hi Wenyu.
> 
> On Tue, Nov 11, 2025 at 09:44:27PM +0800, Wenyu Liu <liuwenyu.0311@...edance.com> wrote:
>> Consider this situation: if we have two cftype arrays A and B
>> which contain the exact same files, and we add this two cftypes
>> with cgroup_add_cftypes().
> 
> Do you have more details about this situation?
> Does this happen with any of the mainline controllers?
> 
> Thanks,
> Michal

On our servers, there a kernel module that registered some control files with cpu controller(with some hacky code, finding and use cgroup_add_dfl_cftypes() via kallsyms_lookup_name()).
For some reason the module name was altered between version iterations.
And due to some accidents, unfortunately, the updated module was reloaded onto the server that previously had the old version installed, resulting in the cgroup becoming unavailable.

Not found this happenned with mainline controllers.

Thanks,
Wenyu