net/iucv: filter frames in afiucv_hs_rcv() by ingress device

{
  "id": "38bd180fdefb8ceac75f97db8dfe2b78624558054c47d683ed6a1cbb6024063a",
  "url": "https://osv.dev/vulnerability/CVE-2026-81003",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net/iucv: filter frames in afiucv_hs_rcv() by ingress device",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net/iucv: filter frames in afiucv_hs_rcv() by ingress device afiucv_hs_rcv() selects a socket from iucv_sk_list by matching four 8-byte name fields in the transport header alone. No check is made against the net_device the frame arrived on. This can cause a frame arriving on any netdev to be delivered to an AF_IUCV socket. Three problems follow. First, a frame arriving over HiperSockets can be delivered to a socket bound to the classic z/VM IUCV transport, which has iucv->hs_dev == NULL. iucv_sock_bind() takes the classic path whenever the requested userid matches iucv_userid, even on a guest that also has a HiperSockets device carrying the same identifier. The child socket created by afiucv_hs_callback_syn() for such a match inherits hs_dev = NULL and transport = AF_IUCV_TRANS_HIPER, so the first send() on it returns -ENODEV. The socket delivered to accept() is unusable. Second, a frame arriving on one netdev can be delivered to a socket bound to a different IQD device. Which can lead to - Accept-queue exhaustion (DoS) - Attacker-controlled peer identity in the child socket - Data injection into existing sockets - Fabric noise on the IQD fabric, where bogus replies are sent - killing established connections Third, all AF_IUCV sockets live in init_net, as iucv_sock_alloc() calls sk_alloc(&init_net, ...). But even frames arriving on netdev devices in a namespace can be delivered to an IUCV socket. So a process",
    "evidence": "osv:CVE-2026-81003",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.270",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.221",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.188",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.157",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.109",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.50",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-81003",
      "aliases": [
        "CVE-2026-81003"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "3881ac441f642d56503818123446f7298442236b"
                },
                {
                  "fixed": "639828ad4d374056167391dbaffd13dd5e5e5ddb"
                },
                {
                  "fixed": "92e5c281f1caa287bb58292f2687c9e3ff3aa23e"
                },
                {
                  "fixed": "712330f8a4293cfd97b0d62b7c7dc01862a16b98"
                },
                {
                  "fixed": "0a5af67e7184c6a0e155c317840bd64b37177af4"
                },
                {
                  "fixed": "dfac2936b83be00035ae176f8252e1c1e1de9207"
                },
                {
                  "fixed": "8e3763f1ccac3fc395f9af2b87114c023ced8a3f"
                },
                {
                  "fixed": "a7f0130a091724e69827ab58e74777a88747e892"
                },
                {
                  "fixed": "80230a18c164a4b5bbc048fe2768b219ac17bc5a"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-81003.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "3.2.0"
                },
                {
                  "fixed": "5.10.270"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
                },
                {
                  "fixed": "5.15.221"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "6.1.188"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.157"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.109"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.50"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-81003.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:29.904469960Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0a5af67e7184c6a0e155c317840bd64b37177af4",
        "https://git.kernel.org/stable/c/639828ad4d374056167391dbaffd13dd5e5e5ddb",
        "https://git.kernel.org/stable/c/712330f8a4293cfd97b0d62b7c7dc01862a16b98",
        "https://git.kernel.org/stable/c/80230a18c164a4b5bbc048fe2768b219ac17bc5a",
        "https://git.kernel.org/stable/c/8e3763f1ccac3fc395f9af2b87114c023ced8a3f",
        "https://git.kernel.org/stable/c/92e5c281f1caa287bb58292f2687c9e3ff3aa23e",
        "https://git.kernel.org/stable/c/a7f0130a091724e69827ab58e74777a88747e892",
        "https://git.kernel.org/stable/c/dfac2936b83be00035ae176f8252e1c1e1de9207",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81003.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-81003",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81003.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-81003",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 496835,
  "published_at": "2026-09-11T19:42:56.172+00:00"
}