CVE-2025-68299
In the Linux kernel, the following vulnerability has been resolved:
afs: Fix delayed allocation of a cell's anonymous key
The allocation of a cell's anonymous key is done in a background thread along with other cell setup such as doing a DNS upcall. In the reported bug, this is triggered by afs_parse_source() parsing the device name given to mount() and calling afs_lookup_cell() with the name of the cell.
The normal key lookup then tries to use the key description on the anonymous authentication key as the reference for request_key() - but it may not yet be set and so an oops can happen.
This has been made more likely to happen by the fix for dynamic lookup failure.
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Fix this by firstly allocating a reference name and attaching it to the afs_cell record when the record is created. It can share the memory allocation with the cell name (unfortunately it can't just overlap the cell name by prepending it with "afs@" as the cell name already has a '.' prepended for other purposes). This reference name is then passed to request_key().
Secondly, the anon key is now allocated on demand at the point a key is requested in afs_request_key() if it is not already allocated. A mutex is used to prevent multiple allocation for a cell.
Thirdly, make afs_request_key_rcu() return NULL if the anonymous key isn't yet allocated (if we need it) and then the caller can return -ECHILD to drop out of RCU-mode and afs_request_key() can be called.
Note that the anonymous key is kind of necessary to make the key lookup cache work as that doesn't currently cache a negative lookup, but it's probably worth some investigation to see if NULL can be used instead.
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.26%
- Percentil entre todas las CVEs puntuadas: 17
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2025-68299",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "fa4ccdccf1489a6dac4369a8c69f11b455b3355c",
"lessThan": "bd18d2cbc9377c6b270c0b7ea44b0e6ed1d99c07",
"versionType": "git"
},
{
"status": "affected",
"version": "7e33b15d5a6578a99ebf189cea34983270ae92dd",
"lessThan": "5613bde937dfac6725e9c3fc766b9d6b8481e55b",
"versionType": "git"
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{
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"versionType": "git"
}
],
"programFiles": [
"fs/afs/cell.c",
"fs/afs/internal.h",
"fs/afs/security.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.17.9",
"lessThan": "6.17.11",
"versionType": "semver"
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],
"programFiles": [
"fs/afs/cell.c",
"fs/afs/internal.h",
"fs/afs/security.c"
],
"defaultStatus": "unaffected"
}
]
}
],
"published": "2025-12-16T16:16:09.400",
"references": [
{
"url": "https://git.kernel.org/stable/c/5613bde937dfac6725e9c3fc766b9d6b8481e55b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/bd18d2cbc9377c6b270c0b7ea44b0e6ed1d99c07",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d27c71257825dced46104eefe42e4d9964bd032e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Deferred",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nafs: Fix delayed allocation of a cell's anonymous key\n\nThe allocation of a cell's anonymous key is done in a background thread\nalong with other cell setup such as doing a DNS upcall. In the reported\nbug, this is triggered by afs_parse_source() parsing the device name given\nto mount() and calling afs_lookup_cell() with the name of the cell.\n\nThe normal key lookup then tries to use the key description on the\nanonymous authentication key as the reference for request_key() - but it\nmay not yet be set and so an oops can happen.\n\nThis has been made more likely to happen by the fix for dynamic lookup\nfailure.\n\nFix this by firstly allocating a reference name and attaching it to the\nafs_cell record when the record is created. It can share the memory\nallocation with the cell name (unfortunately it can't just overlap the cell\nname by prepending it with \"afs@\" as the cell name already has a '.'\nprepended for other purposes). This reference name is then passed to\nrequest_key().\n\nSecondly, the anon key is now allocated on demand at the point a key is\nrequested in afs_request_key() if it is not already allocated. A mutex is\nused to prevent multiple allocation for a cell.\n\nThirdly, make afs_request_key_rcu() return NULL if the anonymous key isn't\nyet allocated (if we need it) and then the caller can return -ECHILD to\ndrop out of RCU-mode and afs_request_key() can be called.\n\nNote that the anonymous key is kind of necessary to make the key lookup\ncache work as that doesn't currently cache a negative lookup, but it's\nprobably worth some investigation to see if NULL can be used instead."
}
],
"lastModified": "2026-08-03T10:16:27.617",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}