Bug 2426249 (CVE-2023-54299)

Summary: CVE-2023-54299 kernel: usb: typec: bus: verify partner exists in typec_altmode_attention
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A NULL pointer dereference flaw was found in the Linux kernel's USB Type-C subsystem. When certain USB hubs perform a data role swap after entering DisplayPort Alt Mode, all alternate modes are unregistered. If the hub continues sending Attention messages afterward, the typec_altmode_attention() function dereferences a NULL partner pointer, causing a kernel crash.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-12-30 13:19:17 UTC 
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.
Comment 1 Alexander B 2025-12-30 22:10:33 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025123032-CVE-2023-54299-ec86@gregkh/T