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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Thu, 24 Feb 2022 20:16:30 +0100
Message-ID: <CAJZ5v0iAkRQuoA+TDU46fR+Xek5rB=tiMNTJ-M28RSyHz2RKiQ@mail.gmail.com>
Subject: Re: [PATCH] thermal: int340x: fix memory leak in int3400_notify()
To:     Chuansheng Liu <chuansheng.liu@intel.com>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>
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On Wed, Feb 23, 2022 at 1:33 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.
>
> Fixes: 38e44da59130 ("thermal: int3400_thermal: process "thermal table
> changed" event")
>
> Cc: linux-pm@vger.kernel.org
> Cc: stable@vger.kernel.org
> Cc: rafael@kernel.org
> Cc: srinivas.pandruvada@linux.intel.com
> Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>

Applied as a fix for 5.17-rc, thanks!

Srinivas, any concerns?

> ---
>  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
>