fkie_cve-2022-48744
Vulnerability from fkie_nvd
Published
2024-06-20 12:15
Modified
2025-09-29 17:30
Severity ?
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; /* 3 1 */
u8 cs_flags; /* 4 1 */
u8 swp_flags; /* 5 1 */
__be16 mss; /* 6 2 */
__be32 flow_table_metadata; /* 8 4 */
union {
struct {
__be16 sz; /* 12 2 */
u8 start[2]; /* 14 2 */
} inline_hdr; /* 12 4 */
struct {
__be16 type; /* 12 2 */
__be16 vlan_tci; /* 14 2 */
} insert; /* 12 4 */
__be32 trailer; /* 12 4 */
}; /* 12 4 */
/* size: 16, cachelines: 1, members: 9 */
/* last cacheline: 16 bytes */
};
struct mlx5_wqe_data_seg {
__be32 byte_count; /* 0 4 */
__be32 lkey; /* 4 4 */
__be64 addr; /* 8 8 */
/* size: 16, cachelines: 1, members: 3 */
/* last cacheline: 16 bytes */
};
So, split the memcpy() so the compiler can reason about the buffer
sizes.
"pahole" shows no size nor member offset changes to struct mlx5e_tx_wqe
nor struct mlx5e_umr_wqe. "objdump -d" shows no meaningful object
code changes (i.e. only source line number induced differences and
optimizations).
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | 5.17 | |
| linux | linux_kernel | 5.17 |
{
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"matchCriteriaId": "C55463E8-26B2-44E1-A5FA-28C2D3640788",
"versionEndExcluding": "5.16.6",
"versionStartIncluding": "4.9",
"vulnerable": true
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"matchCriteriaId": "E6E34B23-78B4-4516-9BD8-61B33F4AC49A",
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"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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 = \u0026wqe-\u003eeth;\n struct mlx5_wqe_data_seg *dseg = wqe-\u003edata;\n\t...\n\tmemcpy(eseg-\u003einline_hdr.start, xdptxd-\u003edata, MLX5E_XDP_MIN_INLINE);\n\ntarget is wqe-\u003eeth.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-\u003edata[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)."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net/mlx5e: Evite el desbordamiento de campos memcpy() En preparaci\u00f3n para FORTIFY_SOURCE, se realizan comprobaciones de los l\u00edmites de campos en tiempo de compilaci\u00f3n y tiempo de ejecuci\u00f3n para memcpy(), memmove() y memset( ), evite escribir intencionalmente en campos vecinos. Utilice matrices flexibles en lugar de matrices de elementos cero (que parecen estar siempre desbordadas) y divida el campo cruzado memcpy() en dos mitades que el compilador pueda verificar adecuadamente los l\u00edmites. Est\u00e1bamos haciendo: #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); ... estructura mlx5_wqe_eth_seg *eseg = \u0026amp;wqe-\u0026gt;eth; struct mlx5_wqe_data_seg *dseg = wqe-\u0026gt;datos; ... memcpy(eseg-\u0026gt;inline_hdr.start, xdptxd-\u0026gt;data, MLX5E_XDP_MIN_INLINE); El objetivo es wqe-\u0026gt;eth.inline_hdr.start (que el compilador considera que tiene un tama\u00f1o de 2 bytes), pero copia 18, con la intenci\u00f3n de escribir a lo largo del inicio (en realidad, vlan_tci, 2 bytes). Los 16 bytes restantes se escriben en wqe-\u0026gt;data[0], cubriendo byte_count (4 bytes), lkey (4 bytes) y addr (8 bytes). estructura mlx5e_tx_wqe { estructura mlx5_wqe_ctrl_seg ctrl; /* 0 16 */ struct mlx5_wqe_eth_seg eth; /* 16 16 */ struct mlx5_wqe_data_seg datos[]; /* 32 0 */ /* tama\u00f1o: 32, l\u00edneas de cach\u00e9: 1, miembros: 3 */ /* \u00faltima l\u00ednea de cach\u00e9: 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; /* 3 1 */ u8 cs_flags; /* 4 1 */ u8 swp_flags; /* 5 1 */ __be16 mss; /* 6 2 */ __be32 flow_table_metadata; /* 8 4 */ uni\u00f3n { estructura { __be16 sz; /* 12 2 */ u8 inicio[2]; /* 14 2 */ } inline_hdr; /* 12 4 */ struct { __be16 tipo; /* 12 2 */ __be16 vlan_tci; /* 14 2 */ } insertar; /* 12 4 */ __be32 remolque; /* 12 4 */ }; /* 12 4 */ /* tama\u00f1o: 16, l\u00edneas de cach\u00e9: 1, miembros: 9 */ /* \u00faltima l\u00ednea de cach\u00e9: 16 bytes */ }; struct mlx5_wqe_data_seg { __be32 byte_count; /* 0 4 */ __be32 lkey; /* 4 4 */ __be64 direcci\u00f3n; /* 8 8 */ /* tama\u00f1o: 16, l\u00edneas de cach\u00e9: 1, miembros: 3 */ /* \u00faltima l\u00ednea de cach\u00e9: 16 bytes */ }; Entonces, divida memcpy() para que el compilador pueda razonar sobre los tama\u00f1os del b\u00fafer. \"pahole\" no muestra cambios de tama\u00f1o ni de compensaci\u00f3n de miembros en la estructura mlx5e_tx_wqe ni en la estructura mlx5e_umr_wqe. \"objdump -d\" no muestra cambios significativos en el c\u00f3digo objeto (es decir, solo diferencias y optimizaciones inducidas por el n\u00famero de l\u00ednea de origen)."
}
],
"id": "CVE-2022-48744",
"lastModified": "2025-09-29T17:30:04.877",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"published": "2024-06-20T12:15:12.700",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/8fbdf8c8b8ab82beab882175157650452c46493e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
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"url": "https://git.kernel.org/stable/c/ad5185735f7dab342fdd0dd41044da4c9ccfef67"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
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"url": "https://git.kernel.org/stable/c/ad5185735f7dab342fdd0dd41044da4c9ccfef67"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-787"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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