[PATCH 2/2] media: rc: do not access device via sysfs after rc_unregister_device()

[Sean Young <sean@mess.org>]

Device drivers do not expect to have change_protocol or wakeup
re-programming to be accesed after rc_unregister_device(). This can
cause the device driver to access deallocated resources.

Signed-off-by: Sean Young <sean@mess.org>
---
 drivers/media/rc/rc-main.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
index 503ae4f3dec3..c629941f309a 100644
--- a/drivers/media/rc/rc-main.c
+++ b/drivers/media/rc/rc-main.c
@@ -1292,6 +1292,10 @@ static ssize_t store_protocols(struct device *device,
 	}
 
 	mutex_lock(&dev->lock);
+	if (!dev->registered) {
+		mutex_unlock(&dev->lock);
+		return -ENODEV;
+	}
 
 	old_protocols = *current_protocols;
 	new_protocols = old_protocols;
@@ -1430,6 +1434,10 @@ static ssize_t store_filter(struct device *device,
 		return -EINVAL;
 
 	mutex_lock(&dev->lock);
+	if (!dev->registered) {
+		mutex_unlock(&dev->lock);
+		return -ENODEV;
+	}
 
 	new_filter = *filter;
 	if (fattr->mask)
@@ -1544,6 +1552,10 @@ static ssize_t store_wakeup_protocols(struct device *device,
 	int i;
 
 	mutex_lock(&dev->lock);
+	if (!dev->registered) {
+		mutex_unlock(&dev->lock);
+		return -ENODEV;
+	}
 
 	allowed = dev->allowed_wakeup_protocols;
 
-- 
2.26.2