{"cve":"CVE-2022-48744","nvd":{"published":"2024-06-20T12:15:12.700","modified":"2026-08-04T10:17:19.190","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Avoid field-overflowing memcpy()\n\nIn preparation for FORTIFY_SOURCE performing compile-time and run-time\nfield bounds checking for memcpy(), memmove(), and memset(), avoid\nintentionally writing across neighboring fields.\n\nUse flexible arrays instead of zero-element arrays (which look like they\nare always overflowing) and split the cross-field memcpy() into two halves\nthat can be appropriately bounds-checked by the compiler.\n\nWe were doing:\n\n\t#define ETH_HLEN  14\n\t#define VLAN_HLEN  4\n\t...\n\t#define MLX5E_XDP_MIN_INLINE (ETH_HLEN + VLAN_HLEN)\n\t...\n        struct mlx5e_tx_wqe      *wqe  = mlx5_wq_cyc_get_wqe(wq, pi);\n\t...\n        struct mlx5_wqe_eth_seg  *eseg = &wqe->eth;\n        struct mlx5_wqe_data_seg *dseg = wqe->data;\n\t...\n\tmemcpy(eseg->inline_hdr.start, xdptxd->data, MLX5E_XDP_MIN_INLINE);\n\ntarget is wqe->eth.inline_hdr.start (which the compiler sees as being\n2 bytes in size), but copying 18, intending to write across start\n(really vlan_tci, 2 bytes). The remaining 16 bytes get written into\nwqe->data[0], covering byte_count (4 bytes), lkey (4 bytes), and addr\n(8 bytes).\n\nstruct mlx5e_tx_wqe {\n        struct mlx5_wqe_ctrl_seg   ctrl;                 /*     0    16 */\n        struct mlx5_wqe_eth_seg    eth;                  /*    16    16 */\n        struct mlx5_wqe_data_seg   data[];               /*    32     0 */\n\n        /* size: 32, cachelines: 1, members: 3 */\n        /* last cacheline: 32 bytes */\n};\n\nstruct mlx5_wqe_eth_seg {\n        u8                         swp_outer_l4_offset;  /*     0     1 */\n        u8                         swp_outer_l3_offset;  /*     1     1 */\n        u8                         swp_inner_l4_offset;  /*     2     1 */\n        u8                         swp_inner_l3_offset;  /*     3     1 */\n        u8                         cs_flags;             /*     4     1 */\n        u8                         swp_flags;            /*     5     1 */\n        __be16                     mss;                  /*     6     2 */\n        __be32                     flow_table_metadata;  /*     8     4 */\n        union {\n                struct {\n                        __be16     sz;                   /*    12     2 */\n                        u8         start[2];             /*    14     2 */\n                } inline_hdr;                            /*    12     4 */\n                struct {\n                        __be16     type;                 /*    12     2 */\n                        __be16     vlan_tci;             /*    14     2 */\n                } insert;                                /*    12     4 */\n                __be32             trailer;              /*    12     4 */\n        };                                               /*    12     4 */\n\n        /* size: 16, cachelines: 1, members: 9 */\n        /* last cacheline: 16 bytes */\n};\n\nstruct mlx5_wqe_data_seg {\n        __be32                     byte_count;           /*     0     4 */\n        __be32                     lkey;                 /*     4     4 */\n        __be64                     addr;                 /*     8     8 */\n\n        /* size: 16, cachelines: 1, members: 3 */\n        /* last cacheline: 16 bytes */\n};\n\nSo, split the memcpy() so the compiler can reason about the buffer\nsizes.\n\n\"pahole\" shows no size nor member offset changes to struct mlx5e_tx_wqe\nnor struct mlx5e_umr_wqe. \"objdump -d\" shows no meaningful object\ncode changes (i.e. only source line number induced differences and\noptimizations).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-787"],"references":["https://git.kernel.org/stable/c/49bcbe531f79fc35bb10020f7695f9f01e4f0ca8","https://git.kernel.org/stable/c/8fbdf8c8b8ab82beab882175157650452c46493e","https://git.kernel.org/stable/c/ad5185735f7dab342fdd0dd41044da4c9ccfef67","https://git.kernel.org/stable/c/8fbdf8c8b8ab82beab882175157650452c46493e","https://git.kernel.org/stable/c/ad5185735f7dab342fdd0dd41044da4c9ccfef67"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:52:00.836172422+00:00"},"epss":{"cve":"CVE-2022-48744","score":0.00602,"percentile":0.4882,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}