From: Sean Young <sean@mess.org>
Date: Sat, 8 Aug 2020 11:38:02 +0000 (+0200)
Subject: media: rc: do not access device via sysfs after rc_unregister_device()
X-Git-Tag: v5.4.64~26
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=5925179bbc64b3393bbea032cf8de080ac51736d;p=users%2Fdwmw2%2Flinux.git

media: rc: do not access device via sysfs after rc_unregister_device()

commit a2e2d73fa28136598e84db9d021091f1b98cbb1a upstream.

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.

Cc: <stable@vger.kernel.org> # 4.16+
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
index 6f80c251f6413..70df83835b5cd 100644
--- a/drivers/media/rc/rc-main.c
+++ b/drivers/media/rc/rc-main.c
@@ -1256,6 +1256,10 @@ 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;
@@ -1394,6 +1398,10 @@ 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)
@@ -1508,6 +1516,10 @@ 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;