CVE-2023-54047: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-54047 is a use-after-free vulnerability in the Linux kernel's DRM/Rockchip dw_hdmi driver that can cause a kernel crash during module removal (rmmod). The flaw arises because the DRM encoder is embedded within the rockchip_hdmi structure, which is freed by the component framework before the main DRM device is destroyed, leaving a dangling reference. It affects Linux kernel versions from the initial commit (1da177e4c3f4) up to the fixes applied in stable releases 6.1.30, 6.3.4, and 6.4. The vulnerability was published on December 24, 2025, and carries an estimated CVSS severity of Medium with an EPSS score of approximately 0.017% (Feedly, ENISA EUVD).

The root cause is a use-after-free (CWE-416) in the drm/rockchip subsystem's dw_hdmi driver. The DRM encoder object is embedded inside the rockchip_hdmi structure, which is allocated and freed as part of the component lifecycle. During module unbind, the component memory (and thus the embedded encoder) is freed before the main DRM device teardown completes, resulting in a use-after-free when the DRM core subsequently attempts to access the encoder. The fix moves the encoder cleanup (drm_encoder_cleanup) above the clk_disable call in the unbind path, mirroring the ordering already used in the bind error path (Feedly, Kernel Git Fix 1).

Successful triggering of this vulnerability causes a kernel crash (system panic or oops) on affected systems using Rockchip SoCs with HDMI output, resulting in a denial of service. Because the flaw is in a kernel driver and involves memory corruption, there is a theoretical risk of privilege escalation or information disclosure if the freed memory is reallocated and manipulated before access, though no such exploitation has been demonstrated. The impact is primarily limited to availability on embedded or single-board computer systems (e.g., Rockchip RK3399-based devices) running affected kernel versions (Feedly, ENISA EUVD).

No public proof-of-concept exploit code or in-the-wild exploitation has been reported for CVE-2023-54047. The vulnerability requires local access to trigger (e.g., executing rmmod on the affected driver), significantly limiting its attack surface. The EPSS score is approximately 0.017%, reflecting a very low probability of exploitation in the near term. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog (Feedly).

The Linux kernel stable tree has released patches addressing this vulnerability in versions 6.1.30, 6.3.4, and 6.4. Users running affected Rockchip HDMI-enabled systems should update to a patched kernel version. As a temporary workaround, avoiding the use of rmmod on the rockchip-drm or related DRM modules can prevent triggering the crash. Distribution-specific patches are tracked by openSUSE (bug 1256398) and Red Hat (Kernel Git Fix 1, Kernel Git Fix 2, Kernel Git Fix 3).