Bug 2420287 (CVE-2023-53780)

Summary: CVE-2023-53780 kernel: drm/amd/display: fix FCLK pstate change underflow
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A calculation flaw was found in the AMD display driver in the Linux kernel. When UCLK p-state is not supported, FCLK p-state change watermarks are incorrectly calculated using dummy values, potentially causing underflow. This can lead to display issues or system instability during power state transitions.
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Description OSIDB Bzimport 2025-12-09 01:05:59 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: fix FCLK pstate change underflow

[Why]
Currently we set FCLK p-state change
watermark calculated based on dummy
p-state latency when UCLK p-state is
not supported

[How]
Calculate FCLK p-state change watermark
based on on FCLK pstate change latency
in case UCLK p-state is not supported
Comment 1 Alexander B 2025-12-10 04:07:50 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025120939-CVE-2023-53780-914d@gregkh/T