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

{
  "id": "27d57bbae91f2e14fb9b7636009556b3e2f2b0fa3fb18f437eee17975049ce71",
  "url": "https://osv.dev/vulnerability/CVE-2026-53313",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "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)",
    "evidence": "osv:CVE-2026-53313",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.191",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.160",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.109",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.50",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-53313",
      "aliases": [
        "CVE-2026-53313"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "2631ac1ac328189031d1aefbbd4929050f72fb23"
                },
                {
                  "fixed": "2afedb8b9262df2a09e62ee7c22530a8c9df5934"
                },
                {
                  "fixed": "1cad9afbb2d559b738b83c498f9c1abdfd327e7f"
                },
                {
                  "fixed": "a71fdbd6e8289e2725d33a9873833459f3b1824f"
                },
                {
                  "fixed": "2ab18de5ebb11c76bfc8087c5a09fbcccd0dea8a"
                },
                {
                  "fixed": "b37a978e6d8c33fbfa4abc5dcca4c7cfc6d01f22"
                },
                {
                  "fixed": "4ae3e16f4b3bf64140f773629b765d605ee079a9"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53313.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.14.0"
                },
                {
                  "fixed": "6.1.191"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.160"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.109"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.50"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53313.json"
          }
        }
      ],
      "modified": "2026-11-01T02:30:20.696083810Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/1cad9afbb2d559b738b83c498f9c1abdfd327e7f",
        "https://git.kernel.org/stable/c/2ab18de5ebb11c76bfc8087c5a09fbcccd0dea8a",
        "https://git.kernel.org/stable/c/2afedb8b9262df2a09e62ee7c22530a8c9df5934",
        "https://git.kernel.org/stable/c/4ae3e16f4b3bf64140f773629b765d605ee079a9",
        "https://git.kernel.org/stable/c/a71fdbd6e8289e2725d33a9873833459f3b1824f",
        "https://git.kernel.org/stable/c/b37a978e6d8c33fbfa4abc5dcca4c7cfc6d01f22",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53313.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-53313",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53313.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-53313",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 501154,
  "published_at": "2026-06-26T19:41:06.568+00:00"
}