Linux Kernel Vulnerability in IO Throttling Mechanism

CVE-2025-38063

What is CVE-2025-38063?

The identified flaw in the Linux kernel's IO throttling mechanism involves the management of flush_bio requests generated during metadata operations. A misconfiguration with REQ_PREFLUSH led to unintended throttling of metadata bio submissions, particularly during high load scenarios. This vulnerability can lead to performance degradation by causing unnecessary delays in processing critical file operations. The fix ensures that flush_bio is conditionally updated, preventing wbt_wait from triggering under normal circumstances, thus improving operational efficiency.

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