Hi,
On 2/18/23 12:53, Armin Wolf wrote:
> If one or both sensor buffers could not be initialized, either
> due to missing hardware support or due to some error during probing,
> the resume handler will encounter undefined behaviour when
> attempting to lock buffers then protected by an uninitialized or
> destroyed mutex.
> Fix this by introducing a "active" flag which is set during probe,
> and only invalidate buffers which where flaged as "active".
>
> Tested on a Dell Inspiron 3505.
>
> Fixes: 3b7eeff93d29 ("platform/x86: dell-ddv: Add hwmon support")
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
> ---
> Changes in v2:
> - move checking of the "active" flag inside
> dell_wmi_ddv_hwmon_cache_invalidate()
Thanks, I've applied this patch to my review-hans branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans
I'll rebase that branch once 6.3-rc1 is out and then push the rebased
patch to the fixes branch and include it in my next 6.3 fixes pull-req
to Linus.
Regards,
Hans
> ---
> drivers/platform/x86/dell/dell-wmi-ddv.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/dell/dell-wmi-ddv.c b/drivers/platform/x86/dell/dell-wmi-ddv.c
> index d547c9d09725..eff4e9649faf 100644
> --- a/drivers/platform/x86/dell/dell-wmi-ddv.c
> +++ b/drivers/platform/x86/dell/dell-wmi-ddv.c
> @@ -96,6 +96,7 @@ struct combined_chip_info {
> };
>
> struct dell_wmi_ddv_sensors {
> + bool active;
> struct mutex lock; /* protect caching */
> unsigned long timestamp;
> union acpi_object *obj;
> @@ -520,6 +521,9 @@ static struct hwmon_channel_info *dell_wmi_ddv_channel_create(struct device *dev
>
> static void dell_wmi_ddv_hwmon_cache_invalidate(struct dell_wmi_ddv_sensors *sensors)
> {
> + if (!sensors->active)
> + return;
> +
> mutex_lock(&sensors->lock);
> kfree(sensors->obj);
> sensors->obj = NULL;
> @@ -530,6 +534,7 @@ static void dell_wmi_ddv_hwmon_cache_destroy(void *data)
> {
> struct dell_wmi_ddv_sensors *sensors = data;
>
> + sensors->active = false;
> mutex_destroy(&sensors->lock);
> kfree(sensors->obj);
> }
> @@ -549,6 +554,7 @@ static struct hwmon_channel_info *dell_wmi_ddv_channel_init(struct wmi_device *w
> return ERR_PTR(ret);
>
> mutex_init(&sensors->lock);
> + sensors->active = true;
>
> ret = devm_add_action_or_reset(&wdev->dev, dell_wmi_ddv_hwmon_cache_destroy, sensors);
> if (ret < 0)
> @@ -852,7 +858,7 @@ static int dell_wmi_ddv_resume(struct device *dev)
> {
> struct dell_wmi_ddv_data *data = dev_get_drvdata(dev);
>
> - /* Force re-reading of all sensors */
> + /* Force re-reading of all active sensors */
> dell_wmi_ddv_hwmon_cache_invalidate(&data->fans);
> dell_wmi_ddv_hwmon_cache_invalidate(&data->temps);
>
> --
> 2.30.2
>
