Race Condition Vulnerability in Linux Kernel's Btrfs Super Block Management

CVE-2026-98907

What is CVE-2026-98907?

A vulnerability has been identified in the Linux kernel affecting the btrfs file system, related to the management of the super block data structure. The issue arises when the function sb_write_pointer() accesses the super block from the block device page cache without proper synchronization. This situation can lead to inconsistent block size settings due to concurrent modifications. To mitigate the risk, the mapping invalidate lock has been implemented around the read_cache_page_gfp() function, ensuring that reads of the super block are serialized against any potential changes in block size.

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