Linux Kernel Vulnerability: Buffer Length Handling Issue in io_uring

CVE-2025-39816

What is CVE-2025-39816?

A vulnerability in the Linux kernel's io_uring interface involves improper handling of user-space mapped buffer lengths. It is crucial to implement the READ_ONCE() function to read the buffer length value into a stable local variable, preventing potential inconsistencies stemming from concurrent modifications. Additionally, ensuring that incremental buffer commits cease upon encountering a zero-sized buffer is essential to avoid unnecessary processing and potential errors. This vulnerability highlights the importance of stringent memory handling practices in kernel development.

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