Description

In the Linux kernel, the following vulnerability has been resolved: vfio/pci: Create persistent INTx handler A vulnerability exists where the eventfd for INTx signaling can be deconfigured, which unregisters the IRQ handler but still allows eventfds to be signaled with a NULL context through the SET_IRQS ioctl or through unmask irqfd if the device interrupt is pending. Ideally this could be solved with some additional locking; the igate mutex serializes the ioctl and config space accesses, and the interrupt handler is unregistered relative to the trigger, but the irqfd path runs asynchronous to those. The igate mutex cannot be acquired from the atomic context of the eventfd wake function. Disabling the irqfd relative to the eventfd registration is potentially incompatible with existing userspace. As a result, the solution implemented here moves configuration of the INTx interrupt handler to track the lifetime of the INTx context object and irq_type configuration, rather than registration of a particular trigger eventfd. Synchronization is added between the ioctl path and eventfd_signal() wrapper such that the eventfd trigger can be dynamically updated relative to in-flight interrupts or irqfd callbacks.

Severity MEDIUM

CVSS Score 5.5

CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE CWE-476

Public Exploit ✅ No

Source NVD

Published 2024-04-05

Updated 2026-06-02

Modified 2026-05-12

Fix URL https://git.kernel.org/stable/c/0e09cf81959d9f12b75ad5c6dd53d237432ed034

Software	From version	Fixed in
debian-linux	—	—
linux-kernel	6.8	6.8.3