CVE-2026-80899 (GCVE-0-2026-80899)
Vulnerability from cvelistv5 – Published: 2026-09-04 17:11 – Updated: 2026-09-04 17:11
VLAI
EPSS
VEX
Title
erofs: remove fscache backend entirely
Summary
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.
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
Severity
No CVSS data available.
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < f6145794f17a27d25f8a84edb80731fb0e07c196
(git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < c37460cd9b2fcb61ec66b7eb4fde737e65ec2a56 (git) Affected: 0 , < 7.1.8 (semver) |
guessed | |
| Linux | Linux |
Unaffected:
7.1.8 , ≤ 7.1.*
(semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"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"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
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"versionType": "git"
},
{
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"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
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"status": "affected",
"version": "0",
"versionType": "semver"
}
]
},
{
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"programFiles": [
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"fs/erofs/fscache.c",
"fs/erofs/inode.c",
"fs/erofs/internal.h",
"fs/erofs/ishare.c",
"fs/erofs/super.c",
"fs/erofs/zdata.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
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"status": "unaffected",
"version": "7.1.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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},
{
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"negate": false,
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"descriptions": [
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"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\u0027s 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"
}
],
"providerMetadata": {
"dateUpdated": "2026-09-04T17:11:14.158Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
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"url": "https://git.kernel.org/stable/c/f6145794f17a27d25f8a84edb80731fb0e07c196"
},
{
"url": "https://git.kernel.org/stable/c/c37460cd9b2fcb61ec66b7eb4fde737e65ec2a56"
}
],
"title": "erofs: remove fscache backend entirely",
"x_generator": {
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},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-80899",
"datePublished": "2026-09-04T17:11:14.158Z",
"dateReserved": "2026-08-26T14:34:25.800Z",
"dateUpdated": "2026-09-04T17:11:14.158Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-80899\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-04T18:17:58.170\",\"lastModified\":\"2026-09-04T18:17:58.170\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"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\u0027s 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\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"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\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"f6145794f17a27d25f8a84edb80731fb0e07c196\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"c37460cd9b2fcb61ec66b7eb4fde737e65ec2a56\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"7.1.8\",\"versionType\":\"semver\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"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\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"7.1.8\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"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\"}]}}",
"suse_vex": {
"aggregate_severity": "not set",
"current_release_date": "2026-09-05T00:24:57Z",
"cve": "CVE-2026-80899",
"id": "CVE-2026-80899",
"initial_release_date": "2026-09-05T00:24:57Z",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-80899",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80899.json",
"version": "2"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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