CVE Catalog

CVE-2026-80899

Low risk· EPSS 4%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.15%

4th percentile - higher than 4% of all known CVEs

Summary

In the Linux kernel, the fscache backend for the EROFS filesystem has been entirely removed. This feature was deprecated for almost two years, and equivalent functionality is now provided by EROFS file-backed mounts and fanotify pre-content hooks. The removal also eliminates implementation issues that were not worth further investigation.

Risk Assessment

Removal of the fscache backend may affect systems using EROFS over fscache, but since the feature was deprecated, the risk is low. Migration to fanotify pre-content hooks is recommended.

Recommendation

Update the Linux kernel to a version containing this change and, if you use EROFS with fscache, plan migration to fanotify pre-content hooks.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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/[email protected]

Vulnerability data from NVD (NIST) · CISA KEV · EPSS