ghsa-94hr-47ff-rmcx
Vulnerability from github
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.
{
"affected": [],
"aliases": [
"CVE-2025-40063"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-28T12:15:40Z",
"severity": null
},
"details": "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.",
"id": "GHSA-94hr-47ff-rmcx",
"modified": "2025-10-28T12:30:17Z",
"published": "2025-10-28T12:30:17Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40063"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/779d3b6f2d32c5f1da6163e959abe1e1ffe2945b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f75f66683ded09f7135aef2e763c245a07c8271a"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
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