{
  "cveId": "CVE-2025-40039",
  "url": "https://patchblox.com/security/cve/CVE-2025-40039",
  "summary": "CVE-2025-40039 is fixed in linux on 1 platform, first by DEBIAN-CVE-2025-40039, released October 28, 2025. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "ksmbd: Fix race condition in RPC handle list access",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  ksmbd: Fix race condition in RPC handle list access  The \u0027sess-\u003Erpc_handle_list\u0027 XArray manages RPC handles within a ksmbd session. Access to this list is intended to be protected by \u0027sess-\u003Erpc_lock\u0027 (an rw_semaphore). However, the locking implementation was flawed, leading to potential race conditions.  In ksmbd_session_rpc_open(), the code incorrectly acquired only a read lock before calling xa_store() and xa_erase(). Since these operations modify the XArray structure, a write lock is required to ensure exclusive access and prevent data corruption from concurrent modifications.  Furthermore, ksmbd_session_rpc_method() accessed the list using xa_load() without holding any lock at all. This could lead to reading inconsistent data or a potential use-after-free if an entry is concurrently removed and the pointer is dereferenced.  Fix these issues by: 1. Using down_write() and up_write() in ksmbd_session_rpc_open()    to ensure exclusive access during XArray modification, and ensuring    the lock is correctly released on error paths. 2. Adding down_read() and up_read() in ksmbd_session_rpc_method()    to safely protect the lookup.",
  "published": "2025-10-28T12:15:37Z",
  "severity": "Moderate",
  "cvss": 4.7,
  "cvssVector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00312,
  "epssPercentile": 0.24321,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-40039",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.162-1",
      "fix": "DEBIAN-CVE-2025-40039",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2025-40039",
      "released": "2025-10-28T12:15:37Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.57-1",
      "fix": "DEBIAN-CVE-2025-40039",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2025-40039",
      "released": "2025-10-28T12:15:37Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.17.6-1",
      "fix": "DEBIAN-CVE-2025-40039",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2025-40039",
      "released": "2025-10-28T12:15:37Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}