Junglewise Threat Intelligence

CVE-2025-39693: Linux Kernel NULL pointer dereference in AMD Display Driver

CVE-2025-39693 · Severity: medium · CVSS 5.5 · Published 2025-09-05

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability exists in the Linux kernel's AMD display driver that could allow a local user to crash the system. The issue occurs when the system fails to properly verify internal display connection data, leading to a system failure (NULL pointer dereference). This primarily impacts system availability, potentially causing a denial-of-service on affected Linux workstations or servers using AMD graphics.

Technical details

A NULL pointer dereference vulnerability exists in the amdgpu_dm_connector_atomic_check function within drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c. The root cause is the lack of validation for the return values of drm_atomic_get_new_connector_state() and drm_atomic_get_old_connector_state(), which can return NULL in certain edge cases. A local attacker with low privileges could potentially trigger this condition to cause a kernel panic (Denial of Service). The issue has been resolved by adding explicit NULL checks and returning -EINVAL if the states are missing. Patches have been backported to multiple stable kernel branches including 5.15.y, 6.1.y, 6.6.y, 6.12.y, and 6.16.y.

Affected products

  • Linux Linux Kernel 4.15 to 5.15.190, 5.16 to 6.1.149, 6.2 to 6.6.103, 6.7 to 6.12.44, 6.13 to 6.16.4

Timeline

  • 2025-09-05: disclosed
  • 2025-09-05: advisory
  • 2025-08-18: patched: Initial fix committed to mainline kernel tree.

References

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