CVE-2026-53313

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Avoid NULL dereference in dc_dmub_srv error paths

In dc_dmub_srv_log_diagnostic_data() and

dc_dmub_srv_enable_dpia_trace().

Both functions check:

if (!dc_dmub_srv || !dc_dmub_srv->dmub)

and then call DC_LOG_ERROR() inside that block.

DC_LOG_ERROR() uses dc_dmub_srv->ctx internally. So if

dc_dmub_srv is NULL, the logging itself can dereference a

NULL pointer and cause a crash.

Fix this by splitting the checks.

First check if dc_dmub_srv is NULL and return immediately.

Then check dc_dmub_srv->dmub and log the error only when

dc_dmub_srv is valid.

Fixes the below:

../display/dc/dc_dmub_srv.c:962 dc_dmub_srv_log_diagnostic_data() error: we previously assumed 'dc_dmub_srv' could be null (see line 961)

../display/dc/dc_dmub_srv.c:1167 dc_dmub_srv_enable_dpia_trace() error: we previously assumed 'dc_dmub_srv' could be null (see line 1166)

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References