linux-kernel - Re: [PATCH v2] fs/resctrl: Restore the rdt_last_cmd_clear() calls after acquiring rdtgroup

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: <de0da633-5d8d-4343-8d23-2c88cb06c1f4@intel.com>
Date: Wed, 4 Jun 2025 11:06:20 -0700
From: Reinette Chatre <reinette.chatre@...el.com>
To: Zeng Heng <zengheng4@...wei.com>, <tony.luck@...el.com>,
	<Dave.Martin@....com>, <fenghuay@...dia.com>, <bp@...en8.de>,
	<james.morse@....com>
CC: <bobo.shaobowang@...wei.com>, <linux-kernel@...r.kernel.org>,
	<x86@...nel.org>
Subject: Re: [PATCH v2] fs/resctrl: Restore the rdt_last_cmd_clear() calls
 after acquiring rdtgroup_mutex

Hi Zeng Heng,

On 6/3/25 5:58 AM, Zeng Heng wrote:
> A lockdep fix removed two rdt_last_cmd_clear() calls that were used
> to clear the last_cmd_status buffer but called without holding the
> required rdtgroup_mutex. The impacted resctrl commands are:
> writing to the cpus or cpus_list files and creating a new monitor
> or control group. With stale data in the last_cmd_status buffer the
> impacted resctrl commands report the stale error on success, or append
> its own failure message to the stale error on failure.
> 
> Consequently, restore the rdt_last_cmd_clear() calls after acquiring
> rdtgroup_mutex.
> 
> Fixes: c8eafe149530 ("x86/resctrl: Fix potential lockdep warning")
> Signed-off-by: Zeng Heng <zengheng4@...wei.com>
> ---

Thank you.

Reviewed-by: Reinette Chatre <reinette.chatre@...el.com>

Reinette