CVE-2023-54299 usb: typec: bus: verify partner exists in typec_altmode_attention
A local attacker with physical access can cause a kernel crash via a null pointer dereference in the USB Type-C subsystem during specific data role swaps.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2023-54299?
CVE-2023-54299 is a vulnerability in Linux, published on 30 Dec 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
usb: typec: bus: verify partner exists in typec_altmode_attention
Some usb hubs will negotiate DisplayPort Alt mode with the device but will then negotiate a data role swap after entering the alt mode. The data role swap causes the device to unregister all alt modes, however the usb hub will still send Attention messages even after failing to reregister the Alt Mode. type_altmode_attention currently does not verify whether or not a device's altmode partner exists, which results in a NULL pointer error when dereferencing the typec_altmode and typec_altmode_ops belonging to the altmode partner.
Verify the presence of a device's altmode partner before sending the Attention message to the Alt Mode driver.
Which versions are affected by CVE-2023-54299?
How do I fix CVE-2023-54299?
Apply the vendor's patch.
Is CVE-2023-54299 being exploited?
There is no known exploitation of CVE-2023-54299 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54299, DEBIAN-CVE-2023-54299, GHSA-4784-9v76-jqjx, UBUNTU-CVE-2023-54299.