CVE-2026-64591: iommu/vt-d: Avoid WARNING in sva unbind path

From: Greg Kroah-Hartman <[email protected]>

Description
===========

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

iommu/vt-d: Avoid WARNING in sva unbind path

The Intel IOMMU driver allows SVA on devices even if they do not support
PCI/PRI. Commit 39c20c4e83b9 ("iommu/vt-d: Only handle IOPF for SVA when
PRI is supported") modified the SVA bind path to allow this configuration
by skipping IOPF enablement when PRI is missing. However, it failed to
update the unbind path.

This creates an imbalance: the unbind path attempts to disable IOPF for
a device that never had it enabled, triggering a WARNING in
intel_iommu_disable_iopf():

 WARNING: drivers/iommu/intel/iommu.c:3475 at intel_iommu_disable_iopf+0x4f/0x90d
 Call Trace:
  <TASK>
  blocking_domain_set_dev_pasid+0x50/0x70
  iommu_detach_device_pasid+0x89/0xc0
  iommu_sva_unbind_device+0x73/0x150
  xe_vm_close_and_put+0x4d2/0x1200 [xe]

Fix this by bypassing IOPF operations for SVA domains on non-PRI hardware
in both the bind and unbind paths.

The Linux kernel CVE team has assigned CVE-2026-64591 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.18.20 with commit ee312bb1052e45cbccaf6abac1012db9ca43150a and fixed in 6.18.39 with commit bb354384f40bb087e7c44f0f0743a23fc945f91d
	Issue introduced in 7.0 with commit 39c20c4e83b9f78988541d829aa34668904e54a0 and fixed in 7.1.4 with commit 477f8dec3b5ae54e8ef3c33bdd2257e47896512e
	Issue introduced in 7.0 with commit 39c20c4e83b9f78988541d829aa34668904e54a0 and fixed in 7.2-rc1 with commit 534b5f98ab7319d8004bbc7dab6481462243e883
	Issue introduced in 6.19.10 with commit 46461dabb95239aa05e31e247cd21151b8406642

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-64591
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/iommu/intel/iommu.h
	drivers/iommu/intel/svm.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/bb354384f40bb087e7c44f0f0743a23fc945f91d
	https://git.kernel.org/stable/c/477f8dec3b5ae54e8ef3c33bdd2257e47896512e
	https://git.kernel.org/stable/c/534b5f98ab7319d8004bbc7dab6481462243e883