CVE-2022-50274

In the Linux kernel, the following vulnerability has been resolved:

media: dvbdev: adopts refcnt to avoid UAF

dvb_unregister_device() is known that prone to use-after-free. That is, the cleanup from dvb_unregister_device() releases the dvb_device even if there are pointers stored in file->private_data still refer to it.

This patch adds a reference counter into struct dvb_device and delays its deallocation until no pointer refers to the object.

This vulnerability is rated as Moderate severity because exploitation requires local access with privileged permissions to interact with or disconnect Digital Video Broadcasting (DVB) devices, limiting exposure to systems utilizing specialized media hardware. In standard enterprise deployments, DVB devices and drivers are rarely active or configured. A local attacker must race device unregistration against active file descriptor operations, which primarily constrains the impact to a denial of service or potential kernel memory corruption.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.