Race Condition in Linux Kernel Affects Hyper-V IRQ Deassignment Functionality

CVE-2026-80896

What is CVE-2026-80896?

A race condition vulnerability exists in the Linux kernel, particularly within the Hyper-V management functions. It occurs in the process of deassigning IRQs, where the lack of proper locking during certain operations leads to inconsistent state management. The mshv_irqfd_deassign() function fails to hold the required lock, allowing potential concurrent access that can disrupt normal operations. Additionally, incorrect handling of node pointers during IRQ deactivation can result in false positives in the active state check, ultimately leading to potential double operations on already altered IRQ nodes. The vulnerability has been addressed by implementing necessary locking mechanisms and ensuring that node pointers are correctly marked during removal, thus enhancing overall reliability.

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