Executive brief
A flaw was discovered in the Linux kernel's network filesystem (netfs) library, which manages how data is cached when reading from or writing to network storage. An error in how the system handles partial data updates could lead to incorrect data being stored or tracked in memory. This could potentially result in data corruption or system instability during specific file writing operations.
Technical details
A logic error exists in the netfs_invalidate_folio() function within the Linux kernel's netfs library. When a partial invalidation region overlaps the beginning of a dirty write cached in a streaming-write folio, the function incorrectly updates the dirty region's offset. Specifically, it sets the start of the dirty region to the beginning of the invalidation region rather than the end, leading to incorrect tracking of dirty data. This issue affects systems using netfs for network-backed storage and has been addressed in multiple stable kernel branches including 6.12.92, 6.18.34, and 7.0.11.
Affected products
- Linux Linux 6.10.8 through 6.11, 6.12.x, 6.18.x, 7.0.x
Timeline
- 2026-05-12: disclosed: Initial patch submitted by David Howells
- 2026-07-19: advisory: CVE-2026-64157 published in NVD