CVE-2024-27437 vfio/pci: Disable auto-enable of exclusive INTx IRQ
A race condition in the Linux kernel's vfio/pci driver can cause an unrecoverable interrupt state, leading to denial of service for users of virtualized PCI devices.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-27437?
CVE-2024-27437 is a medium-severity vulnerability in Debian Debian Linux, published on 5 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2024-27437?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2024-27437?
Apply the vendor's patch.
Is CVE-2024-27437 being exploited?
There is no known exploitation of CVE-2024-27437 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-59261, BELL-CVE-2024-27437, DEBIAN-CVE-2024-27437, GHSA-5mg2-h7qv-m552, UBUNTU-CVE-2024-27437.