Executive brief
A vulnerability in the AMD display driver for the Linux kernel could allow a local user to cause a system crash. The issue occurs when the system incorrectly handles certain types of DisplayPort connections, leading to a kernel panic. This primarily impacts system availability and could be used to disrupt operations on affected hardware.
Technical details
The vulnerability exists in the dcn401_hwseq.c component of the AMD display driver (DRM) within the Linux kernel. Specifically, the function get_phyd32clk_src was being called on DisplayPort Inter-Adapter (DPIA) links without a proper signal type check. This results in an invalid access to link encoder structures that are not present for DPIA links, leading to a kernel crash (NULL pointer dereference or similar memory corruption). The fix introduces a signal type validation to ensure the encoder is only accessed for compatible 128b/132b signals. Patches have been released across multiple stable kernel branches including 6.12.y, 6.18.y, and 6.19.y.
Affected products
- Linux Linux Kernel 6.11 to 6.12.75, 6.13 to 6.18.16, 6.19 to 6.19.6
Timeline
- 2025-12-10: other: Initial patch authored by AMD developer
- 2026-01-05: other: Patch committed to mainline kernel
- 2026-05-06: disclosed: CVE published