CVE-2024-27437 Information

Description

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.

Reference

https://git.kernel.org/stable/c/139dfcc4d723ab13469881200c7d80f49d776060 https://git.kernel.org/stable/c/2a4a666c45107206605b7b5bc20545f8aabc4fa2 https://git.kernel.org/stable/c/3b3491ad0f80d913e7d255941d4470f4a4d9bfda https://git.kernel.org/stable/c/bf0bc84a20e6109ab07d5dc072067bd01eb931ec https://git.kernel.org/stable/c/fe9a7082684eb059b925c535682e68c34d487d43