CVE-2025-38240: drm/mediatek: dp: drm_err => dev_err in HPD path to avoid NULL ptr

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-04-18 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: drm/mediatek: dp: drm_err => dev_err in HPD path to avoid NULL ptr The function mtk_dp_wait_hpd_asserted() may be called before the `mtk_dp->drm_dev` pointer is assigned in mtk_dp_bridge_attach(). Specifically it can be called via this callpath: - mtk_edp_wait_hpd_asserted - [panel probe] - dp_aux_ep_probe Using "drm" level prints anywhere in this callpath causes a NULL pointer dereference. Change the error message directly in mtk_dp_wait_hpd_asserted() to dev_err() to avoid this. Also change the error messages in mtk_dp_parse_capabilities(), which is called by mtk_dp_wait_hpd_asserted(). While touching these prints, also add the error code to them to make future debugging easier.

Affected products

Linux kernel: from 6.6 before 6.6.87; from 6.7 before 6.12.23; from 6.13 before 6.13.11; from 6.14 before 6.14.2 — fixed in 6.12.23, 6.13.11, 6.14.2, 6.6.87

How to fix

Upgrade to a fixed version: Linux kernel 6.12.23, 6.13.11, 6.14.2, 6.6.87. Check the vendor advisory for mitigations.

References

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