CVE-2024-56760: In the Linux kernel, the following vulnerability has been resolved: PCI/MSI: Handle lack of irqdomain gracefully Alexandre observed a warning emitte...

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.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.20%

10.2th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	>= 6.2, < 6.6.69	—
Linux	Linux Kernel	>= 6.7, < 6.12.8	—
Linux	Linux Kernel	6.13	Rc1

References

Timeline

Published: Jan 6, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-56760?

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.

How severe is CVE-2024-56760?

CVE-2024-56760 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.20% probability of exploitation in the next 30 days.

How do I fix CVE-2024-56760?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.