CVE-2025-21956: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Assign normalized_pix_clk when color depth = 14 [WHY & HOW] A warning message "WARNING: CPU: 4 PID: 459 at ... /dc_resource.c:3397 calculate_phy_pix_clks+0xef/0x100 [amdgpu]" occurs because the display_color_depth == COLOR_DEPTH_141414 is not handled. This is observed in Radeon RX 6600 XT. It is fixed by assigning pix_clk * (14 * 3) / 24 - same as the rests. Also fixes the indentation in get_norm_pix_clk. (cherry picked from commit 274a87eb389f58eddcbc5659ab0b180b37e92775)

Affected products

• Linux Linux Kernel: from 4.15, before 5.4.292 (fixed in 5.4.292); from 5.5, before 5.10.236 (fixed in 5.10.236); from 5.11, before 5.15.180 (fixed in 5.15.180); from 5.16, before 6.1.132 (fixed in 6.1.132); from 6.2, before 6.6.84 (fixed in 6.6.84); from 6.7, before 6.12.20 (fixed in 6.12.20); …

Published 2025-04-01. Last modified 2026-06-17.