FKIE_CVE-2025-40063

Vulnerability from fkie_nvd - Published: 2025-10-28 12:15 - Updated: 2026-10-19 21:10
Severity
7.0 (High) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: crypto: comp - Use same definition of context alloc and free ops In commit 42d9f6c77479 ("crypto: acomp - Move scomp stream allocation code into acomp"), the crypto_acomp_streams struct was made to rely on having the alloc_ctx and free_ctx operations defined in the same order as the scomp_alg struct. But in that same commit, the alloc_ctx and free_ctx members of scomp_alg may be randomized by structure layout randomization, since they are contained in a pure ops structure (containing only function pointers). If the pointers within scomp_alg are randomized, but those in crypto_acomp_streams are not, then the order may no longer match. This fixes the problem by removing the union from scomp_alg so that both crypto_acomp_streams and scomp_alg will share the same definition of alloc_ctx and free_ctx, ensuring they will always have the same layout.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/779d3b6f2d32c5f1da6163e959abe1e1ffe2945b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f75f66683ded09f7135aef2e763c245a07c8271a
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "crypto/842.c",
            "crypto/lz4.c",
            "crypto/lz4hc.c",
            "crypto/lzo-rle.c",
            "crypto/lzo.c",
            "drivers/crypto/nx/nx-common-powernv.c",
            "drivers/crypto/nx/nx-common-pseries.c",
            "include/crypto/internal/scompress.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "779d3b6f2d32c5f1da6163e959abe1e1ffe2945b",
              "status": "affected",
              "version": "42d9f6c774790d290c175e8775ce9f1366438098",
              "versionType": "git"
            },
            {
              "lessThan": "f75f66683ded09f7135aef2e763c245a07c8271a",
              "status": "affected",
              "version": "42d9f6c774790d290c175e8775ce9f1366438098",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "crypto/842.c",
            "crypto/lz4.c",
            "crypto/lz4hc.c",
            "crypto/lzo-rle.c",
            "crypto/lzo.c",
            "drivers/crypto/nx/nx-common-powernv.c",
            "drivers/crypto/nx/nx-common-pseries.c",
            "include/crypto/internal/scompress.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: comp - Use same definition of context alloc and free ops\n\nIn commit 42d9f6c77479 (\"crypto: acomp - Move scomp stream allocation\ncode into acomp\"), the crypto_acomp_streams struct was made to rely on\nhaving the alloc_ctx and free_ctx operations defined in the same order\nas the scomp_alg struct. But in that same commit, the alloc_ctx and\nfree_ctx members of scomp_alg may be randomized by structure layout\nrandomization, since they are contained in a pure ops structure\n(containing only function pointers). If the pointers within scomp_alg\nare randomized, but those in crypto_acomp_streams are not, then\nthe order may no longer match. This fixes the problem by removing the\nunion from scomp_alg so that both crypto_acomp_streams and scomp_alg\nwill share the same definition of alloc_ctx and free_ctx, ensuring\nthey will always have the same layout."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\ncrypto: comp - Usar la misma definici\u00f3n de operaciones de asignaci\u00f3n y liberaci\u00f3n de contexto\n\nEn el commit 42d9f6c77479 (\u0027crypto: acomp - Mover el c\u00f3digo de asignaci\u00f3n de flujo scomp a acomp\u0027), se hizo que la estructura crypto_acomp_streams dependiera de tener las operaciones alloc_ctx y free_ctx definidas en el mismo orden que la estructura scomp_alg. Pero en ese mismo commit, los miembros alloc_ctx y free_ctx de scomp_alg pueden ser aleatorizados por la aleatorizaci\u00f3n del dise\u00f1o de la estructura, ya que est\u00e1n contenidos en una estructura de operaciones pura (que contiene solo punteros a funciones). Si los punteros dentro de scomp_alg son aleatorizados, pero los de crypto_acomp_streams no lo son, entonces el orden puede dejar de coincidir. Esto soluciona el problema al eliminar la uni\u00f3n de scomp_alg para que tanto crypto_acomp_streams como scomp_alg compartan la misma definici\u00f3n de alloc_ctx y free_ctx, asegurando que siempre tendr\u00e1n el mismo dise\u00f1o."
    }
  ],
  "id": "CVE-2025-40063",
  "lastModified": "2026-10-19T21:10:00.160",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.0,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2025-10-28T12:15:40.730",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/779d3b6f2d32c5f1da6163e959abe1e1ffe2945b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f75f66683ded09f7135aef2e763c245a07c8271a"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Deferred"
}



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