[PATCH 6.1 1/2] HID: asus: use spinlock to protect concurrent accesses

[PATCH 6.1 1/2] HID: asus: use spinlock to protect concurrent accesses

[Stefan Ghinea]

From: Pietro Borrello <borrello@diag.uniroma1.it>

commit 315c537068a13f0b5681d33dd045a912f4bece6f upstream

asus driver has a worker that may access data concurrently.
Proct the accesses using a spinlock.

Fixes: af22a610bc38 ("HID: asus: support backlight on USB keyboards")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
Link: https://lore.kernel.org/r/20230125-hid-unregister-leds-v4-4-7860c5763c38@diag.uniroma1.it
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
---
 drivers/hid/hid-asus.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index f99752b998f3..9f767baf39fb 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -98,6 +98,7 @@ struct asus_kbd_leds {
 	struct hid_device *hdev;
 	struct work_struct work;
 	unsigned int brightness;
+	spinlock_t lock;
 	bool removed;
 };
 
@@ -495,7 +496,12 @@ static void asus_kbd_backlight_set(struct led_classdev *led_cdev,
 {
 	struct asus_kbd_leds *led = container_of(led_cdev, struct asus_kbd_leds,
 						 cdev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&led->lock, flags);
 	led->brightness = brightness;
+	spin_unlock_irqrestore(&led->lock, flags);
+
 	schedule_work(&led->work);
 }
 
@@ -503,8 +509,14 @@ static enum led_brightness asus_kbd_backlight_get(struct led_classdev *led_cdev)
 {
 	struct asus_kbd_leds *led = container_of(led_cdev, struct asus_kbd_leds,
 						 cdev);
+	enum led_brightness brightness;
+	unsigned long flags;
 
-	return led->brightness;
+	spin_lock_irqsave(&led->lock, flags);
+	brightness = led->brightness;
+	spin_unlock_irqrestore(&led->lock, flags);
+
+	return brightness;
 }
 
 static void asus_kbd_backlight_work(struct work_struct *work)
@@ -512,11 +524,14 @@ static void asus_kbd_backlight_work(struct work_struct *work)
 	struct asus_kbd_leds *led = container_of(work, struct asus_kbd_leds, work);
 	u8 buf[] = { FEATURE_KBD_REPORT_ID, 0xba, 0xc5, 0xc4, 0x00 };
 	int ret;
+	unsigned long flags;
 
 	if (led->removed)
 		return;
 
+	spin_lock_irqsave(&led->lock, flags);
 	buf[4] = led->brightness;
+	spin_unlock_irqrestore(&led->lock, flags);
 
 	ret = asus_kbd_set_report(led->hdev, buf, sizeof(buf));
 	if (ret < 0)
@@ -584,6 +599,7 @@ static int asus_kbd_register_leds(struct hid_device *hdev)
 	drvdata->kbd_backlight->cdev.brightness_set = asus_kbd_backlight_set;
 	drvdata->kbd_backlight->cdev.brightness_get = asus_kbd_backlight_get;
 	INIT_WORK(&drvdata->kbd_backlight->work, asus_kbd_backlight_work);
+	spin_lock_init(&drvdata->kbd_backlight->lock);
 
 	ret = devm_led_classdev_register(&hdev->dev, &drvdata->kbd_backlight->cdev);
 	if (ret < 0) {
@@ -1119,9 +1135,13 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
 static void asus_remove(struct hid_device *hdev)
 {
 	struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
+	unsigned long flags;
 
 	if (drvdata->kbd_backlight) {
+		spin_lock_irqsave(&drvdata->kbd_backlight->lock, flags);
 		drvdata->kbd_backlight->removed = true;
+		spin_unlock_irqrestore(&drvdata->kbd_backlight->lock, flags);
+
 		cancel_work_sync(&drvdata->kbd_backlight->work);
 	}
 
-- 
2.39.1

[PATCH 6.1 2/2] HID: asus: use spinlock to safely schedule workers

[Stefan Ghinea]

From: Pietro Borrello <borrello@diag.uniroma1.it>

commit 4ab3a086d10eeec1424f2e8a968827a6336203df upstream

Use spinlocks to deal with workers introducing a wrapper
asus_schedule_work(), and several spinlock checks.
Otherwise, asus_kbd_backlight_set() may schedule led->work after the
structure has been freed, causing a use-after-free.

Fixes: af22a610bc38 ("HID: asus: support backlight on USB keyboards")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
Link: https://lore.kernel.org/r/20230125-hid-unregister-leds-v4-5-7860c5763c38@diag.uniroma1.it
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
---
 drivers/hid/hid-asus.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index 9f767baf39fb..d1094bb1aa42 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -491,6 +491,16 @@ static int rog_nkey_led_init(struct hid_device *hdev)
 	return ret;
 }
 
+static void asus_schedule_work(struct asus_kbd_leds *led)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&led->lock, flags);
+	if (!led->removed)
+		schedule_work(&led->work);
+	spin_unlock_irqrestore(&led->lock, flags);
+}
+
 static void asus_kbd_backlight_set(struct led_classdev *led_cdev,
 				   enum led_brightness brightness)
 {
@@ -502,7 +512,7 @@ static void asus_kbd_backlight_set(struct led_classdev *led_cdev,
 	led->brightness = brightness;
 	spin_unlock_irqrestore(&led->lock, flags);
 
-	schedule_work(&led->work);
+	asus_schedule_work(led);
 }
 
 static enum led_brightness asus_kbd_backlight_get(struct led_classdev *led_cdev)
@@ -526,9 +536,6 @@ static void asus_kbd_backlight_work(struct work_struct *work)
 	int ret;
 	unsigned long flags;
 
-	if (led->removed)
-		return;
-
 	spin_lock_irqsave(&led->lock, flags);
 	buf[4] = led->brightness;
 	spin_unlock_irqrestore(&led->lock, flags);
-- 
2.39.1

Re: [PATCH 6.1 1/2] HID: asus: use spinlock to protect concurrent accesses

[Greg KH]

On Thu, Mar 02, 2023 at 12:38:52AM +0200, Stefan Ghinea wrote:
> From: Pietro Borrello <borrello@diag.uniroma1.it>
> 
> commit 315c537068a13f0b5681d33dd045a912f4bece6f upstream
> 
> asus driver has a worker that may access data concurrently.
> Proct the accesses using a spinlock.
> 
> Fixes: af22a610bc38 ("HID: asus: support backlight on USB keyboards")
> Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
> Link: https://lore.kernel.org/r/20230125-hid-unregister-leds-v4-4-7860c5763c38@diag.uniroma1.it
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
> ---
>  drivers/hid/hid-asus.c | 22 +++++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)

What about 6.2.y as well?

Why skip that?

thanks,

greg k-h