Race Condition in Linux Kernel's btrfs File System

CVE-2026-93255

What is CVE-2026-93255?

A vulnerability has been identified in the Linux kernel related to the btrfs file system, where a race condition could potentially trigger false alerts during the read and unmount operations. This occurs in the method 'invalidate_and_check_btree_folios()', which checks for the 'EXTENT_BUFFER_READING' flag. Due to the timing of operations between threads, it may incorrectly warn about lingering references to extent buffers, leading to potential data consistency problems. To rectify this, a helper function has been implemented to ensure that the reading flag is cleared while holding the appropriate locks, thus eliminating the critical race window.

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