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Fencer Vulns
no cvss —

CVE-2026-64591 json

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

published 2026-08-06 3 mo ago modified 2026-08-17 2 mo ago also EUVD-2026-53778

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

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.

Patch / fix

  • Linux Linux 6.18.39, 6.20, 7.1.4, 7.2
  • linux Debian 14 7.1.4-1

debian advisories DEBIAN-CVE-2026-64591

  • linux Ubuntu 26.04 LTS 7.0.0-31.31
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1012.12
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1011.11
  • linux-gke Ubuntu 26.04 LTS 7.0.0-1006.7
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1013.13
  • linux-azure Ubuntu 26.04 LTS 7.0.0-1014.14
  • linux-raspi Ubuntu 26.04 LTS 7.0.0-1019.19
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-31.31.1

ubuntu advisories UBUNTU-CVE-2026-64591

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-source openSUSE Tumbleweed 7.1.7-1.1

opensuse advisories openSUSE-SU-2026:11476-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-64591 updated cvss 5.5

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

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-selftests-internal Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.