CVE-2026-53313

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)

Weakness

The product dereferences a pointer that it expects to be valid but is NULL.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/4ae3e16f4b3bf64140f773629b765d605ee079a9
• https://git.kernel.org/stable/c/b37a978e6d8c33fbfa4abc5dcca4c7cfc6d01f22