Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220222020021.19640-1-chuansheng.liu@intel.com>
In-Reply-To: <20220222020021.19640-1-chuansheng.liu@intel.com>
From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Tue, 22 Feb 2022 13:34:19 +0100
Message-ID: <CAJZ5v0hziz4Eyk7qFgYMM4YYEZTpd_faukMczg7hnou9yP9yiQ@mail.gmail.com>
Subject: Re: [PATCH] thermal: int340x: fix memory leak in int3400_notify()
To:     Chuansheng Liu <chuansheng.liu@intel.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        "Zhang, Rui" <rui.zhang@intel.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Please resend this with a CC to linux-pm@vger.kernel.org.  Thanks!

On Tue, Feb 22, 2022 at 3:13 AM Chuansheng Liu <chuansheng.liu@intel.com> wrote:
>
> It is easy to hit the below memory leaks in my TigerLake platform:
>
> --
> unreferenced object 0xffff927c8b91dbc0 (size 32):
>   comm "kworker/0:2", pid 112, jiffies 4294893323 (age 83.604s)
>   hex dump (first 32 bytes):
>     4e 41 4d 45 3d 49 4e 54 33 34 30 30 20 54 68 65  NAME=INT3400 The
>     72 6d 61 6c 00 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5  rmal.kkkkkkkkkk.
>   backtrace:
>     [<ffffffff9c502c3e>] __kmalloc_track_caller+0x2fe/0x4a0
>     [<ffffffff9c7b7c15>] kvasprintf+0x65/0xd0
>     [<ffffffff9c7b7d6e>] kasprintf+0x4e/0x70
>     [<ffffffffc04cb662>] int3400_notify+0x82/0x120 [int3400_thermal]
>     [<ffffffff9c8b7358>] acpi_ev_notify_dispatch+0x54/0x71
>     [<ffffffff9c88f1a7>] acpi_os_execute_deferred+0x17/0x30
>     [<ffffffff9c2c2c0a>] process_one_work+0x21a/0x3f0
>     [<ffffffff9c2c2e2a>] worker_thread+0x4a/0x3b0
>     [<ffffffff9c2cb4dd>] kthread+0xfd/0x130
>     [<ffffffff9c201c1f>] ret_from_fork+0x1f/0x30
> ---
>
> Fix it by calling kfree() accordingly.
>
> Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
> ---
>  drivers/thermal/intel/int340x_thermal/int3400_thermal.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> index 72acb1f61849..4f478812cb51 100644
> --- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> +++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> @@ -404,6 +404,10 @@ static void int3400_notify(acpi_handle handle,
>         thermal_prop[3] = kasprintf(GFP_KERNEL, "EVENT=%d", therm_event);
>         thermal_prop[4] = NULL;
>         kobject_uevent_env(&priv->thermal->device.kobj, KOBJ_CHANGE, thermal_prop);
> +       kfree(thermal_prop[0]);
> +       kfree(thermal_prop[1]);
> +       kfree(thermal_prop[2]);
> +       kfree(thermal_prop[3]);
>  }
>
>  static int int3400_thermal_get_temp(struct thermal_zone_device *thermal,
> --
> 2.25.0.rc2
>