Vulnerability CVE-2024-27437
Published: 2024-04-05

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.

 References:
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
Copyright 2026, cxsecurity.com

 

Back to Top