{
  "cveId": "CVE-2026-89809",
  "url": "https://patchblox.com/security/cve/CVE-2026-89809",
  "summary": "CVE-2026-89809 is fixed in linux on 1 platform by DEBIAN-CVE-2026-89809 (version 7.2.6-1), released September 23, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "drm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  drm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds  Reading /sys/kernel/debug/kfd/mqds while a process holds an active KFD queue triggers a NULL pointer dereference because the for loop that calls mqd_mgr-\u003Edebugfs_show_mqd() is incorrectly placed outside the if (pqn-\u003Eq) block that initializes mqd_mgr.  The queue list can contain entries where pqn-\u003Eq is NULL (kernel queues where only pqn-\u003Ekq is valid). In the original code:    if (pqn-\u003Eq) {       ...       mqd_mgr = q-\u003Edevice-\u003Edqm-\u003Emqd_mgrs[mqd_type];       size = mqd_mgr-\u003Emqd_stride(...);   }    for (xcc = 0; xcc \u003C num_xccs; xcc\u002B\u002B) {  // WRONG: outside if block       mqd = q-\u003Emqd \u002B size * xcc;       r = mqd_mgr-\u003Edebugfs_show_mqd(m, mqd);   }  When iterating over a queue node where pqn-\u003Eq is NULL: 1. The if (pqn-\u003Eq) block is skipped 2. mqd_mgr remains uninitialized (NULL from declaration) 3. The for loop executes anyway 4. mqd_mgr-\u003Edebugfs_show_mqd(m, mqd) dereferences NULL  The crash manifests as:    BUG: kernel NULL pointer dereference, address: 0000000000000000   #PF: supervisor instruction fetch in kernel mode   RIP: 0010:0x0   Call Trace:    pqm_debugfs_mqds\u002B0x10c/0x1d0 [amdgpu]    kfd_debugfs_mqds_by_process\u002B0x9b/0x110 [amdgpu]    seq_read_iter\u002B0x132/0x4b0    ...  Fix by moving the for loop inside the if (pqn-\u003Eq) block, so mqd_mgr and related variables are only used when properly initialized.  (cherry picked from commit 8bfe29d5c798940f797aa24135d2734c3ffce9de)",
  "published": "2026-09-16T11:16:46Z",
  "severity": "Moderate",
  "cvss": 5.5,
  "epss": 0.00198,
  "epssPercentile": 0.09573,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-89809",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.6-1",
      "fix": "DEBIAN-CVE-2026-89809",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-89809",
      "released": "2026-09-23T19:19:02Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}