CVE-2024-27437

In the Linux kernel, the following vulnerability has been resolved:

vfio/pci: Disable auto-enable of exclusive INTx IRQ

Currently for devices requiring masking at the irqchip for INTx, ie.

devices without DisINTx support, the IRQ is enabled in request_irq()

and subsequently disabled as necessary to align with the masked status

flag. This presents a window where the interrupt could fire between

these events, resulting in the IRQ incrementing the disable depth twice.

This would be unrecoverable for a user since the masked flag prevents

nested enables through vfio.

Instead, invert the logic using IRQF_NO_AUTOEN such that exclusive INTx

is never auto-enabled, then unmask as required.