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

Summary

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)

Timeline

1. Jun 26, 2026, 7:41 PM UTCCVE published
2. Oct 21, 2026, 12:42 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 2631ac1ac328189031d1aefbbd4929050f72fb23 · fixed in 1cad9afbb2d559b738b83c498f9c1abdfd327e7f; From 2631ac1ac328189031d1aefbbd4929050f72fb23 · fixed in a71fdbd6e8289e2725d33a9873833459f3b1824f; From 2631ac1ac328189031d1aefbbd4929050f72fb23 · fixed in 2ab18de5ebb11c76bfc8087c5a09fbcccd0dea8a; From 2631ac1ac328189031d1aefbbd4929050f72fb23 · fixed in b37a978e6d8c33fbfa4abc5dcca4c7cfc6d01f22; From 2631ac1ac328189031d1aefbbd4929050f72fb23 · fixed in 4ae3e16f4b3bf64140f773629b765d605ee079a9

• Linux Linux

  5.14

• KernelLinux

  From 5.14.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.109; From 6.13.0 · fixed in 6.18.50; From 6.19.0 · fixed in 7.0.10

References 5