Linux Kernel Vulnerability in File Mapping Calculations

CVE-2026-31648

What is CVE-2026-31648?

A vulnerability exists in the Linux kernel related to memory management that affects file mapping calculations. The issue arises from an overflow in the 'nr_pages' calculation within the function 'filemap_map_pages()', which can lead to incorrect page mappings beyond the allocated space of large folios. This may potentially corrupt page fields, resulting in unpredictable crashes and problematic system states. It can be triggered by concurrent operations manipulating file attributes, particularly during intensive memory stress testing. Proper coding standards and logic adjustments are vital to mitigate this flaw.

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