In the Linux kernel, the following vulnerability has been resolved:

iommu/s390: Make attach succeed when the device was surprise removed

When a PCI device is removed with surprise hotplug, there may still be
attempts to attach the device to the default domain as part of tear down
via (__iommu_release_dma_ownership()), or because the removal happens
during probe (__iommu_probe_device()). In both cases zpci_register_ioat()
fails with a cc value indicating that the device handle is invalid. This
is because the device is no longer part of the instance as far as the
hypervisor is concerned.

Currently this leads to an error return and s390_iommu_attach_device()
fails. This triggers the WARN_ON() in __iommu_group_set_domain_nofail()
because attaching to the default domain must never fail.

With the device fenced by the hypervisor no DMAs to or from memory are
possible and the IOMMU translations have no effect. Proceed as if the
registration was successful and let the hotplug event handling clean up
the device.

This is similar to how devices in the error state are handled since
commit 59bbf596791b ("iommu/s390: Make attach succeed even if the device
is in error state") except that for removal the domain will not be
registered later. This approach was also previously discussed at the
link.

Handle both cases, error state and removal, in a helper which checks if
the error needs to be propagated or ignored. Avoid magic number
condition codes by using the pre-existing, but never used, defines for
PCI load/store condition codes and rename them to reflect that they
apply to all PCI instructions.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 09 Oct 2025 13:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Thu, 09 Oct 2025 10:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: iommu/s390: Make attach succeed when the device was surprise removed When a PCI device is removed with surprise hotplug, there may still be attempts to attach the device to the default domain as part of tear down via (__iommu_release_dma_ownership()), or because the removal happens during probe (__iommu_probe_device()). In both cases zpci_register_ioat() fails with a cc value indicating that the device handle is invalid. This is because the device is no longer part of the instance as far as the hypervisor is concerned. Currently this leads to an error return and s390_iommu_attach_device() fails. This triggers the WARN_ON() in __iommu_group_set_domain_nofail() because attaching to the default domain must never fail. With the device fenced by the hypervisor no DMAs to or from memory are possible and the IOMMU translations have no effect. Proceed as if the registration was successful and let the hotplug event handling clean up the device. This is similar to how devices in the error state are handled since commit 59bbf596791b ("iommu/s390: Make attach succeed even if the device is in error state") except that for removal the domain will not be registered later. This approach was also previously discussed at the link. Handle both cases, error state and removal, in a helper which checks if the error needs to be propagated or ignored. Avoid magic number condition codes by using the pre-existing, but never used, defines for PCI load/store condition codes and rename them to reflect that they apply to all PCI instructions.
Title iommu/s390: Make attach succeed when the device was surprise removed
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-10-09T09:47:35.601Z

Reserved: 2025-04-16T07:20:57.149Z

Link: CVE-2025-39958

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-10-09T10:15:37.867

Modified: 2025-10-09T10:15:37.867

Link: CVE-2025-39958

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-10-09T12:51:14Z