Vulnerability in Linux Kernel Affecting Event Processing Mechanism

CVE-2026-80920

What is CVE-2026-80920?

This vulnerability in the Linux kernel arises from improper handling of eventfd signaling within io_uring when queued from a wakeup handler. The flaw can cause unintended interaction when the signal is sent inline, potentially leading to feedback loops in epoll processing. By introducing IOU_F_TWQ_IN_WAKE, the system can manage this signaling correctly, deferring the eventfd signal until it is safe to do so, thus preventing recursive execution issues and maintaining stable operation.

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