net/mlx5e: Avoid field-overflowing memcpy()

{
  "id": "e865018ef3c55af382a3c7792c10b803440eb4964f9898f1b7665fa05189c1b0",
  "url": "https://osv.dev/vulnerability/CVE-2022-48744",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net/mlx5e: Avoid field-overflowing memcpy()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Avoid field-overflowing memcpy() In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memcpy(), memmove(), and memset(), avoid intentionally writing across neighboring fields. Use flexible arrays instead of zero-element arrays (which look like they are always overflowing) and split the cross-field memcpy() into two halves that can be appropriately bounds-checked by the compiler. We were doing: #define ETH_HLEN 14 #define VLAN_HLEN 4 ... #define MLX5E_XDP_MIN_INLINE (ETH_HLEN + VLAN_HLEN) ... struct mlx5e_tx_wqe *wqe = mlx5_wq_cyc_get_wqe(wq, pi); ... struct mlx5_wqe_eth_seg *eseg = &wqe->eth; struct mlx5_wqe_data_seg *dseg = wqe->data; ... memcpy(eseg->inline_hdr.start, xdptxd->data, MLX5E_XDP_MIN_INLINE); target is wqe->eth.inline_hdr.start (which the compiler sees as being 2 bytes in size), but copying 18, intending to write across start (really vlan_tci, 2 bytes). The remaining 16 bytes get written into wqe->data[0], covering byte_count (4 bytes), lkey (4 bytes), and addr (8 bytes). struct mlx5e_tx_wqe { struct mlx5_wqe_ctrl_seg ctrl; /* 0 16 */ struct mlx5_wqe_eth_seg eth; /* 16 16 */ struct mlx5_wqe_data_seg data[]; /* 32 0 */ /* size: 32, cachelines: 1, members: 3 */ /* last cacheline: 32 bytes */ }; struct mlx5_wqe_eth_seg { u8 swp_outer_l4_offset; /* 0 1 */ u8 swp_outer_l3_offset; /* 1 1 */ u8 swp_inner_l4_offset; /* 2 1 */ u8 swp_inner_l3_offset;",
    "evidence": "osv:CVE-2022-48744",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.248",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.16.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2022-48744",
      "aliases": [
        "CVE-2022-48744"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "b5503b994ed5ed8dbfe821317e7b5b38acb065c5"
                },
                {
                  "fixed": "49bcbe531f79fc35bb10020f7695f9f01e4f0ca8"
                },
                {
                  "fixed": "8fbdf8c8b8ab82beab882175157650452c46493e"
                },
                {
                  "fixed": "ad5185735f7dab342fdd0dd41044da4c9ccfef67"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-48744.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "4.9.0"
                },
                {
                  "fixed": "5.10.248"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
                },
                {
                  "fixed": "5.16.6"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-48744.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.523344597Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/49bcbe531f79fc35bb10020f7695f9f01e4f0ca8",
        "https://git.kernel.org/stable/c/8fbdf8c8b8ab82beab882175157650452c46493e",
        "https://git.kernel.org/stable/c/ad5185735f7dab342fdd0dd41044da4c9ccfef67",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48744.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2022-48744",
        "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/2022/48xxx/CVE-2022-48744.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2022-48744",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 513530,
  "published_at": "2024-06-20T11:13:27.979+00:00"
}