ghsa-8xqx-42cr-fv84
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix out-of-bounds dynptr write in bpf_crypto_crypt
Stanislav reported that in bpf_crypto_crypt() the destination dynptr's size is not validated to be at least as large as the source dynptr's size before calling into the crypto backend with 'len = src_len'. This can result in an OOB write when the destination is smaller than the source.
Concretely, in mentioned function, psrc and pdst are both linear buffers fetched from each dynptr:
psrc = __bpf_dynptr_data(src, src_len); [...] pdst = __bpf_dynptr_data_rw(dst, dst_len); [...] err = decrypt ? ctx->type->decrypt(ctx->tfm, psrc, pdst, src_len, piv) : ctx->type->encrypt(ctx->tfm, psrc, pdst, src_len, piv);
The crypto backend expects pdst to be large enough with a src_len length that can be written. Add an additional src_len > dst_len check and bail out if it's the case. Note that these kfuncs are accessible under root privileges only.
{
"affected": [],
"aliases": [
"CVE-2025-39917"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-01T08:15:34Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix out-of-bounds dynptr write in bpf_crypto_crypt\n\nStanislav reported that in bpf_crypto_crypt() the destination dynptr\u0027s\nsize is not validated to be at least as large as the source dynptr\u0027s\nsize before calling into the crypto backend with \u0027len = src_len\u0027. This\ncan result in an OOB write when the destination is smaller than the\nsource.\n\nConcretely, in mentioned function, psrc and pdst are both linear\nbuffers fetched from each dynptr:\n\n psrc = __bpf_dynptr_data(src, src_len);\n [...]\n pdst = __bpf_dynptr_data_rw(dst, dst_len);\n [...]\n err = decrypt ?\n ctx-\u003etype-\u003edecrypt(ctx-\u003etfm, psrc, pdst, src_len, piv) :\n ctx-\u003etype-\u003eencrypt(ctx-\u003etfm, psrc, pdst, src_len, piv);\n\nThe crypto backend expects pdst to be large enough with a src_len length\nthat can be written. Add an additional src_len \u003e dst_len check and bail\nout if it\u0027s the case. Note that these kfuncs are accessible under root\nprivileges only.",
"id": "GHSA-8xqx-42cr-fv84",
"modified": "2025-10-01T09:30:25Z",
"published": "2025-10-01T09:30:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-39917"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0126358df12d6f476f79251d9c398ac5c1b3062d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c4be24ef0510c146dca4671effb127e97631534b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f9bb6ffa7f5ad0f8ee0f53fc4a10655872ee4a14"
}
],
"schema_version": "1.4.0",
"severity": []
}
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.