Race Condition Vulnerability in Linux Kernel nilfs2 Product by Linux Community

CVE-2025-21811

Summary

A race condition in the nilfs2 implementation of the Linux kernel may lead to unsafe memory access in the event of asynchronous operations. Specifically, when the file system transitions to a read-only state, the nilfs_lookup_dirty_data_buffers function is at risk of encountering buffers that have lost their protection status. This may occur if nilfs_clear_folio_dirty is invoked simultaneously, resulting in potential use-after-free vulnerabilities as buffers could be inadvertently freed. To mitigate this risk, improvements were made to the locking mechanisms within the related functions, ensuring that access to buffers remains safely synchronized.

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