linux-kernel - Re: [PATCH 2/7] cpufreq: Init policy->rwsem before it may be possibly used

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: <CAJZ5v0jHjyPMwB5dt9qv01nXAN5z+Kbztb_Mho0Py0cUqZO+sg@mail.gmail.com>
Date: Mon, 23 Jun 2025 17:29:54 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Lifeng Zheng <zhenglifeng1@...wei.com>
Cc: rafael@...nel.org, viresh.kumar@...aro.org, ionela.voinescu@....com, 
	linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org, linuxarm@...wei.com, 
	jonathan.cameron@...wei.com, zhanjie9@...ilicon.com, lihuisong@...wei.com, 
	yubowen8@...wei.com
Subject: Re: [PATCH 2/7] cpufreq: Init policy->rwsem before it may be possibly used

On Mon, Jun 23, 2025 at 3:34 PM Lifeng Zheng <zhenglifeng1@...wei.com> wrote:
>
> In cpufreq_policy_put_kobj(), policy->rwsem is used. But in
> cpufreq_policy_alloc(), if freq_qos_add_notifier() returns an error, error
> path via err_kobj_remove or err_min_qos_notifier will be reached and
> cpufreq_policy_put_kobj() will be called before policy->rwsem is
> initialized. Thus, the calling of init_rwsem() should be moved to where
> before these two error paths can be reached.

Since this is a fix, any chance to add a Fixes: tag here?

> Signed-off-by: Lifeng Zheng <zhenglifeng1@...wei.com>
> ---
>  drivers/cpufreq/cpufreq.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 1bc665b5bba8..efc1f4ac85cb 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -1284,6 +1284,8 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
>                 goto err_free_real_cpus;
>         }
>
> +       init_rwsem(&policy->rwsem);
> +
>         freq_constraints_init(&policy->constraints);
>
>         policy->nb_min.notifier_call = cpufreq_notifier_min;
> @@ -1306,7 +1308,6 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
>         }
>
>         INIT_LIST_HEAD(&policy->policy_list);
> -       init_rwsem(&policy->rwsem);
>         spin_lock_init(&policy->transition_lock);
>         init_waitqueue_head(&policy->transition_wait);
>         INIT_WORK(&policy->update, handle_update);
> --
> 2.33.0
>