CVE-2023-54299

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usb: typec: bus: verify partner exists in typec_altmode_attention<br /> <br /> Some usb hubs will negotiate DisplayPort Alt mode with the device<br /> but will then negotiate a data role swap after entering the alt<br /> mode. The data role swap causes the device to unregister all alt<br /> modes, however the usb hub will still send Attention messages<br /> even after failing to reregister the Alt Mode. type_altmode_attention<br /> currently does not verify whether or not a device&amp;#39;s altmode partner<br /> exists, which results in a NULL pointer error when dereferencing<br /> the typec_altmode and typec_altmode_ops belonging to the altmode<br /> partner.<br /> <br /> Verify the presence of a device&amp;#39;s altmode partner before sending<br /> the Attention message to the Alt Mode driver.