vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting

{
  "id": "c3b6ef98a11eba01432729cab3d0e3c361a4e1728ff8e3e9c59be7865b6de130",
  "url": "https://osv.dev/vulnerability/CVE-2026-52994",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting virtio_transport_init_zcopy_skb() uses iter->count as the size argument for msg_zerocopy_realloc(), which in turn passes it to mm_account_pinned_pages() for RLIMIT_MEMLOCK accounting. However, this function is called after virtio_transport_fill_skb() has already consumed the iterator via __zerocopy_sg_from_iter(), so on the last skb, iter->count will be 0, skipping the RLIMIT_MEMLOCK enforcement. Pass pkt_len (the total bytes being sent) as an explicit parameter to virtio_transport_init_zcopy_skb() instead of reading the already-consumed iter->count. This matches TCP and UDP, which both call msg_zerocopy_realloc() with the original message size.",
    "evidence": "osv:CVE-2026-52994",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.33",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-52994",
      "aliases": [
        "CVE-2026-52994"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "581512a6dc939ef122e49336626ae159f3b8a345"
                },
                {
                  "fixed": "6af1736b5810bc8a4a43a8518530113f5a757dc1"
                },
                {
                  "fixed": "d0117950075f0a9d5944980784c719d8ebcd4bff"
                },
                {
                  "fixed": "1cb36e252211506f51095fe7ced8286cc77b4c80"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-52994.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.18.33"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-52994.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:42.011315013Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/1cb36e252211506f51095fe7ced8286cc77b4c80",
        "https://git.kernel.org/stable/c/6af1736b5810bc8a4a43a8518530113f5a757dc1",
        "https://git.kernel.org/stable/c/d0117950075f0a9d5944980784c719d8ebcd4bff",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52994.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-52994",
        "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/2026/52xxx/CVE-2026-52994.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-52994",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 509285,
  "published_at": "2026-06-24T16:29:07.36+00:00"
}