{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "302fef75512b2c8329a3f5efab1ae7ba2562387a"
            },
            {
              "fixed": "9e785f004cbc56390479b77375726ea9b0d1a8a6"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c"
            },
            {
              "fixed": "7de55bba69cbf0f9280daaea385daf08bc076121"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "1d6abf145615dbfe267ce3b0a271f95e3780e18e"
            },
            {
              "fixed": "a5c6f6d6ceefed2d5210ee420fb75f8362461f46"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "ce8507ee82c888126d8e7565e27c016308d24cde"
            },
            {
              "fixed": "6d7e5a918c1d0aad06db0e17677b66fc9a471021"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "1dfd062caa165ec9d7ee0823087930f3ab8a6294"
            },
            {
              "fixed": "48623ec358c1c600fa1e38368746f933e0f1a617"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.6.130"
            },
            {
              "fixed": "6.6.131"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.12.78"
            },
            {
              "fixed": "6.12.80"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.18.19"
            },
            {
              "fixed": "6.18.21"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.9"
            },
            {
              "fixed": "6.19.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31444.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free and NULL deref in smb_grant_oplock()\n\nsmb_grant_oplock() has two issues in the oplock publication sequence:\n\n1) opinfo is linked into ci-\u003em_op_list (via opinfo_add) before\n   add_lease_global_list() is called.  If add_lease_global_list()\n   fails (kmalloc returns NULL), the error path frees the opinfo\n   via __free_opinfo() while it is still linked in ci-\u003em_op_list.\n   Concurrent m_op_list readers (opinfo_get_list, or direct iteration\n   in smb_break_all_levII_oplock) dereference the freed node.\n\n2) opinfo-\u003eo_fp is assigned after add_lease_global_list() publishes\n   the opinfo on the global lease list.  A concurrent\n   find_same_lease_key() can walk the lease list and dereference\n   opinfo-\u003eo_fp-\u003ef_ci while o_fp is still NULL.\n\nFix by restructuring the publication sequence to eliminate post-publish\nfailure:\n\n- Set opinfo-\u003eo_fp before any list publication (fixes NULL deref).\n- Preallocate lease_table via alloc_lease_table() before opinfo_add()\n  so add_lease_global_list() becomes infallible after publication.\n- Keep the original m_op_list publication order (opinfo_add before\n  lease list) so concurrent opens via same_client_has_lease() and\n  opinfo_get_list() still see the in-flight grant.\n- Use opinfo_put() instead of __free_opinfo() on err_out so that\n  the RCU-deferred free path is used.\n\nThis also requires splitting add_lease_global_list() to take a\npreallocated lease_table and changing its return type from int to void,\nsince it can no longer fail.",
  "id": "CVE-2026-31444",
  "modified": "2026-07-08T05:39:32.165148416Z",
  "published": "2026-04-22T13:53:41.351Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/48623ec358c1c600fa1e38368746f933e0f1a617"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6d7e5a918c1d0aad06db0e17677b66fc9a471021"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7de55bba69cbf0f9280daaea385daf08bc076121"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9e785f004cbc56390479b77375726ea9b0d1a8a6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a5c6f6d6ceefed2d5210ee420fb75f8362461f46"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31444.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31444"
    },
    {
      "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 and NULL deref in smb_grant_oplock()"
}