{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "e1b73b64271d706079370b58b81292dafd373163"
            },
            {
              "fixed": "58e866711b234571b0ce342c43d153a4786b32b8"
            },
            {
              "fixed": "012a026bae0212952b423a842b7e2c0bf21f8e7a"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.0.0"
            },
            {
              "fixed": "7.2.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89809.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds\n\nReading /sys/kernel/debug/kfd/mqds while a process holds an active KFD\nqueue triggers a NULL pointer dereference because the for loop that\ncalls mqd_mgr-\u003edebugfs_show_mqd() is incorrectly placed outside the\nif (pqn-\u003eq) block that initializes mqd_mgr.\n\nThe queue list can contain entries where pqn-\u003eq is NULL (kernel queues\nwhere only pqn-\u003ekq is valid). In the original code:\n\n  if (pqn-\u003eq) {\n      ...\n      mqd_mgr = q-\u003edevice-\u003edqm-\u003emqd_mgrs[mqd_type];\n      size = mqd_mgr-\u003emqd_stride(...);\n  }\n\n  for (xcc = 0; xcc \u003c num_xccs; xcc++) {  // WRONG: outside if block\n      mqd = q-\u003emqd + size * xcc;\n      r = mqd_mgr-\u003edebugfs_show_mqd(m, mqd);\n  }\n\nWhen iterating over a queue node where pqn-\u003eq is NULL:\n1. The if (pqn-\u003eq) block is skipped\n2. mqd_mgr remains uninitialized (NULL from declaration)\n3. The for loop executes anyway\n4. mqd_mgr-\u003edebugfs_show_mqd(m, mqd) dereferences NULL\n\nThe crash manifests as:\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000000\n  #PF: supervisor instruction fetch in kernel mode\n  RIP: 0010:0x0\n  Call Trace:\n   pqm_debugfs_mqds+0x10c/0x1d0 [amdgpu]\n   kfd_debugfs_mqds_by_process+0x9b/0x110 [amdgpu]\n   seq_read_iter+0x132/0x4b0\n   ...\n\nFix by moving the for loop inside the if (pqn-\u003eq) block, so mqd_mgr\nand related variables are only used when properly initialized.\n\n(cherry picked from commit 8bfe29d5c798940f797aa24135d2734c3ffce9de)",
  "id": "CVE-2026-89809",
  "modified": "2026-09-19T03:30:44.115635373Z",
  "published": "2026-09-16T10:30:42.445Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/012a026bae0212952b423a842b7e2c0bf21f8e7a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/58e866711b234571b0ce342c43d153a4786b32b8"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89809.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89809"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "drm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds"
}