CVE-2026-80899
In the Linux kernel, the following vulnerability has been resolved:
erofs: remove fscache backend entirely
EROFS over fscache was introduced to provide image lazy pulling functionality. After the feature landed, the fscache subsystem made netfs a new hard dependency, which is unexpected for a local filesystem and has an kernel-defined caching hierarchy which could be inflexible compared to the fanotify pre-content hooks. Therefore, this feature has been deprecated for almost two years.
As EROFS file-backed mounts and fanotify pre-content hooks both upstream for a while and already providing equivalent functionality (erofs-utils has supported fanotify pre-content hooks), let's remove the fscache backend now.
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The main application of this feature is Nydus [1], and they plan to move to use fanotify pre-content hooks in the near future too.
I hope this patch can be merged into Linux 7.2, which is also motivated by newly found implementation issues [2][3] that are not worth investigating given the deprecation and limited development resources. The associated fscache/cachefiles cleanup patch will follow separately through the vfs tree (netfs) later: it seems fine since the codebase is isolated by CONFIG_CACHEFILES_ONDEMAND.
[1] https://github.com/dragonflyoss/nydus/blob/v2.1.0/docs/nydus-fscache.md [2] https://github.com/dragonflyoss/nydus/pull/1824 [3] https://lore.kernel.org/r/20260619135800.1594811-1-michael.bommarito@gmail.com
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: 0.20%
- Percentil entre todas las CVEs puntuadas: 9
- 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)
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{
"id": "CVE-2026-80899",
"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": "a1bafc3109d713ed83f73d61ba5cb1e6fd80fdbc",
"lessThan": "f6145794f17a27d25f8a84edb80731fb0e07c196",
"versionType": "git"
},
{
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"versionType": "git"
}
],
"programFiles": [
"Documentation/filesystems/erofs.rst",
"fs/erofs/Kconfig",
"fs/erofs/Makefile",
"fs/erofs/data.c",
"fs/erofs/fscache.c",
"fs/erofs/inode.c",
"fs/erofs/internal.h",
"fs/erofs/ishare.c",
"fs/erofs/super.c",
"fs/erofs/zdata.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.9"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.9",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"Documentation/filesystems/erofs.rst",
"fs/erofs/Kconfig",
"fs/erofs/Makefile",
"fs/erofs/data.c",
"fs/erofs/fscache.c",
"fs/erofs/inode.c",
"fs/erofs/internal.h",
"fs/erofs/ishare.c",
"fs/erofs/super.c",
"fs/erofs/zdata.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-04T18:17:58.170",
"references": [
{
"url": "https://git.kernel.org/stable/c/c37460cd9b2fcb61ec66b7eb4fde737e65ec2a56",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f6145794f17a27d25f8a84edb80731fb0e07c196",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: remove fscache backend entirely\n\nEROFS over fscache was introduced to provide image lazy pulling\nfunctionality. After the feature landed, the fscache subsystem made\nnetfs a new hard dependency, which is unexpected for a local filesystem\nand has an kernel-defined caching hierarchy which could be inflexible\ncompared to the fanotify pre-content hooks. Therefore, this feature has\nbeen deprecated for almost two years.\n\nAs EROFS file-backed mounts and fanotify pre-content hooks both upstream\nfor a while and already providing equivalent functionality (erofs-utils\nhas supported fanotify pre-content hooks), let's remove the fscache\nbackend now.\n\nThe main application of this feature is Nydus [1], and they plan to move\nto use fanotify pre-content hooks in the near future too.\n\nI hope this patch can be merged into Linux 7.2, which is also motivated\nby newly found implementation issues [2][3] that are not worth\ninvestigating given the deprecation and limited development resources.\nThe associated fscache/cachefiles cleanup patch will follow separately\nthrough the vfs tree (netfs) later: it seems fine since the codebase is\nisolated by CONFIG_CACHEFILES_ONDEMAND.\n\n[1] https://github.com/dragonflyoss/nydus/blob/v2.1.0/docs/nydus-fscache.md\n[2] https://github.com/dragonflyoss/nydus/pull/1824\n[3] https://lore.kernel.org/r/20260619135800.1594811-1-michael.bommarito@gmail.com"
}
],
"lastModified": "2026-09-07T15:17:33.410",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}