Executive brief
A vulnerability in the Linux kernel's AMD display driver could allow a local user to cause a system hang. The issue occurs when the system incorrectly handles power transitions for certain display outputs, leading to a state where the hardware becomes unresponsive. This primarily impacts system availability and could disrupt operations or require a hard reboot.
Technical details
A race condition or improper state transition exists in the AMD Display Core (DC) driver, specifically within the PHY Finite State Machine (FSM) for TMDS signals on DCN35 hardware. When disabling TMDS output, the driver may incorrectly turn off the PHY PLL, causing the Output Transmission Group (OTG) to become stuck. This state prevents the Display Hub Virtual Memory (DCHVM) from acknowledging invalidations, potentially leading to a system hang or triggering an IOMMU watchdog timeout. The fix involves ensuring the transition to the PLL_ON state is handled atomically to prevent pre-emption during the sequence. Patches have been backported from DCN401 to DCN35 to resolve the issue.
Affected products
- Linux Linux Kernel 6.7 to 6.19.6
Timeline
- 2026-05-06: advisory: Initial CVE publication
- 2026-05-11: other: NVD analysis and enrichment completed