{
  "affected": [
    {
      "ranges": [
        {
          "events": [
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              "introduced": "dd4e4c811898410e6a3ae3b63207b7c542860907"
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
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              "introduced": "aa7253c2393f6dcd6a1468b0792f6da76edad917"
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            {
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            },
            {
              "fixed": "7470511d085af1c7a043a60e53d52b512d5a10b1"
            },
            {
              "fixed": "16a1ecf39c217e3d164bd32ef2a4f650abc067fa"
            },
            {
              "fixed": "77bb0bbfcc4e777ca653174689e5e363f8ee63d1"
            },
            {
              "fixed": "1c89da3baa2b1f269178afa87dc30479b8535776"
            },
            {
              "fixed": "0c054227479ed7e36ebccb3a558bc0ef698264f6"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
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            },
            {
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            },
            {
              "last_affected": "ff20f1875889dbe4a67c9298e609d7c88cf6456d"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
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              "introduced": "5.15.61"
            },
            {
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            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
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              "introduced": "5.18.18"
            },
            {
              "fixed": "5.19"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
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            },
            {
              "fixed": "5.20"
            }
          ],
          "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": "5.15.212"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.178"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.0.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.12.97"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.18.40"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "7.1.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72422.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free of conn-\u003epreauth_info in concurrent SMB2 NEGOTIATE\n\nconn-\u003epreauth_info is shared connection state (struct\npreauth_integrity_info, kmalloc-96) that is allocated and freed by the\nSMB2 NEGOTIATE handler and read by the response send path.\n\nsmb2_handle_negotiate() allocates conn-\u003epreauth_info, and on a\ndeassemble_neg_contexts() failure kfrees it and sets it to NULL. Both the\nallocation and the free/NULL happen under ksmbd_conn_lock(conn) (the\nconnection srv_mutex), which is held across the whole handler body.\n\nThe response send path smb3_preauth_hash_rsp(), called from the send:\nblock of __handle_ksmbd_work(), reads conn-\u003epreauth_info and dereferences\nconn-\u003epreauth_info-\u003ePreauth_HashValue (via\nksmbd_gen_preauth_integrity_hash()) without taking conn_lock. When a\nclient drives two SMB2 NEGOTIATE requests on the same connection, one\nworker can free conn-\u003epreauth_info on the failing-negotiate path while a\nconcurrent send-path worker is reading it, producing a slab\nuse-after-free read (KASAN-confirmed).\n\nThe send-path read tested conn-\u003epreauth_info for NULL but raced with the\nfree that occurs between the NULL check and the dereference, so the NULL\nguard alone does not close the window.\n\nSerialize the NEGOTIATE-branch read in smb3_preauth_hash_rsp() under\nksmbd_conn_lock(conn) and re-check conn-\u003epreauth_info inside the lock.\nBecause the negotiate handler holds conn_lock across its kfree + NULL\nassignment, a reader that also takes conn_lock either runs fully before\nthe allocation or fully after the NULL store, and can never observe the\nfreed-but-not-yet-NULLed pointer. ksmbd_gen_preauth_integrity_hash()\ntakes no locks itself (it only computes a SHA-512 over the buffer), so\nno lock-ordering inversion is introduced, and conn_lock is a sleepable\nmutex which is safe on this send path (it already performs network I/O).",
  "id": "CVE-2026-72422",
  "modified": "2026-08-18T03:31:04.363828502Z",
  "published": "2026-08-15T05:56:41.090Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0c054227479ed7e36ebccb3a558bc0ef698264f6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/16a1ecf39c217e3d164bd32ef2a4f650abc067fa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1c89da3baa2b1f269178afa87dc30479b8535776"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7470511d085af1c7a043a60e53d52b512d5a10b1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/77bb0bbfcc4e777ca653174689e5e363f8ee63d1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c7bef84740d1d57848c74f6f5b996606e43ea4fe"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d0a469122e7bf8338fec1949fb1e8e1290ed8caa"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72422.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72422"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "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 of conn-\u003epreauth_info in concurrent SMB2 NEGOTIATE"
}