Data Integrity Flaw in Linux Kernel's Btrfs File System

CVE-2026-89772

What is CVE-2026-89772?

A vulnerability in the Linux kernel related to the Btrfs file system's memory management has been identified that compromises data integrity. A flaw in the way dirty flags are managed during writeback operations can lead to scenarios where processes manipulating memory-mapped files can corrupt data. When a bio operation is submitted for a folio, the integrity of that data can be jeopardized if simultaneous write operations occur, potentially resulting in invalid checksums, lost writes, and data corruption. This issue could affect various aspects of the file system, including large folios, submerged sectors, and inline extents. The risk of modifying data while it is compressed or during other operations further exacerbates the problem. Users and administrators of affected Linux kernel versions should take precautions to mitigate the risks associated with this vulnerability.

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