{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "8df4bcdb0a4232192b2445256c39b787d58ef14d"
            },
            {
              "fixed": "0000a7780e0e446a28a273572f6ea8f7f582f694"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "c8efcc786146a951091588e5fa7e3c754850cb3c"
            },
            {
              "fixed": "e33c65f011980b4ad4abfd93585ec2079856368f"
            },
            {
              "fixed": "3d6682726c2d3a46d31dae88b8166786b09b03ad"
            },
            {
              "fixed": "b34fc42cfe922e551f7a27d3ac3bb016e41d7dd9"
            },
            {
              "fixed": "235e32320a470fcd3998fb3774f2290a0eb302a1"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6.6.32"
            },
            {
              "fixed": "6.6.140"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.6.140"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.84"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.9.0"
            },
            {
              "fixed": "6.18.25"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "7.0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31718.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger\n\nWhen a durable file handle survives session disconnect (TCP close without\nSMB2_LOGOFF), session_fd_check() sets fp-\u003econn = NULL to preserve the\nhandle for later reconnection. However, it did not clean up the byte-range\nlocks on fp-\u003elock_list.\n\nLater, when the durable scavenger thread times out and calls\n__ksmbd_close_fd(NULL, fp), the lock cleanup loop did:\n\n    spin_lock(\u0026fp-\u003econn-\u003ellist_lock);\n\nThis caused a slab use-after-free because fp-\u003econn was NULL and the\noriginal connection object had already been freed by\nksmbd_tcp_disconnect().\n\nThe root cause is asymmetric cleanup: lock entries (smb_lock-\u003eclist) were\nleft dangling on the freed conn-\u003elock_list while fp-\u003econn was nulled out.\n\nTo fix this issue properly, we need to handle the lifetime of\nsmb_lock-\u003eclist across three paths:\n - Safely skip clist deletion when list is empty and fp-\u003econn is NULL.\n - Remove the lock from the old connection's lock_list in\n   session_fd_check()\n - Re-add the lock to the new connection's lock_list in\n   ksmbd_reopen_durable_fd().",
  "id": "CVE-2026-31718",
  "modified": "2026-07-08T05:36:00.003052227Z",
  "published": "2026-05-01T13:56:12.680Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0000a7780e0e446a28a273572f6ea8f7f582f694"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/235e32320a470fcd3998fb3774f2290a0eb302a1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3d6682726c2d3a46d31dae88b8166786b09b03ad"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b34fc42cfe922e551f7a27d3ac3bb016e41d7dd9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e33c65f011980b4ad4abfd93585ec2079856368f"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31718.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31718"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger"
}