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TI-2026-33619 Aliases CVE-2026-45894GHSA-8pm8-q9qq-gqgp

iommu/vt-d: Clear Present bit before tearing down PASID entry

Priority LOW 35CWE-362Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 14 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Clear Present bit before tearing down PASID entry The Intel VT-d Scalable Mode PASID table entry consists of 512 bits (64 bytes). When tearing down an entry, the current implementation zeros the entire 64-byte structure immediately using multiple 64-bit writes. Since the IOMMU hardware may fetch these 64 bytes using multiple internal transactions (e.g., four 128-bit bursts), updating or zeroing the entire entry while it is active (P=1) risks a "torn" read. If a hardware fetch occurs simultaneously with the CPU zeroing the entry, the hardware could observe an inconsistent state, leading to unpredictable behavior or spurious faults. Follow the "Guidance to Software for Invalidations" in the VT-d spec (Section 6.5.3.3) by implementing the recommended ownership handshake: 1. Clear only the 'Present' (P) bit of the PASID entry. 2. Use a dma_wmb() to ensure the cleared bit is visible to hardware before proceeding. 3. Execute the required invalidation sequence (PASID cache, IOTLB, and Device-TLB flush) to ensure the hardware has released all cached references. 4. Only after the flushes are complete, zero out the remaining fields of the PASID entry. Also, add a dma_wmb() in pasid_set_present() to ensure that all other fields of the PASID entry are visible to the hardware before the Present bit is set.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00131 2nd percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.1.191, 6.6.160, 6.12.75 +3Red Hat: 4 advisoriesRed Hat: 14 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux5.0 and later6.1.191, 6.6.160, 6.12.75, 6.18.14, 6.19.4, 7.0Patch availableCNA
  • Linux VendorLinux Affected 5.0 and later Fixed in 6.1.191, 6.6.160, 6.12.75, 6.18.14, 6.19.4, 7.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*5.0 to before 6.12.75; 6.13 to before 6.18.14; 6.19 to before 6.19.4VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.0 to before 6.12.75; 6.13 to before 6.18.14; 6.19 to before 6.19.4 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.75, 6.18.14, 6.19.4, 7.0

Red Hat 4 advisories

  • RHSA-2026:70459 Released 2026-09-23 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.50.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.50.1.el9_8, kernel-64k-devel-5.14.0-687.50.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.50.1.el9_8, kernel-64k-5.14.0-687.50.1.el9_8, kernel-64k-core-5.14.0-687.50.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.50.1.el9_8, libperf-5.14.0-687.50.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.50.1.el9_8, kernel-rt-64k-5.14.0-687.50.1.el9_8, kernel-rt-64k-core-5.14.0-687.50.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.50.1.el9_8, kernel-rt-core-5.14.0-687.50.1.el9_8, kernel-rt-debug-5.14.0-687.50.1.el9_8 +9
  • RHSA-2026:70498 Released 2026-09-23 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.58.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.58.1.el10_2, kernel-64k-devel-6.12.0-211.58.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.58.1.el10_2, kernel-64k-6.12.0-211.58.1.el10_2, kernel-64k-core-6.12.0-211.58.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.58.1.el10_2, libperf-6.12.0-211.58.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.58.1.el10_2, kernel-rt-64k-6.12.0-211.58.1.el10_2, kernel-rt-64k-core-6.12.0-211.58.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.58.1.el10_2, kernel-rt-core-6.12.0-211.58.1.el10_2, kernel-rt-debug-6.12.0-211.58.1.el10_2 +9
  • RHSA-2026:70402 Released 2026-09-22 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.166.1.el8_10, kernel-4.18.0-553.166.1.el8_10, kernel-abi-stablelists-4.18.0-553.166.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.166.1.el8_10
Show 1 more Red Hat advisories
  • RHSA-2026:70403 Released 2026-09-22 · Red Hat rating Important
    kernel-rt security, bug fix, and enhancement update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-core-4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-debug-4.18.0-553.166.1.rt7.507.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-core-4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-debug-4.18.0-553.166.1.rt7.507.el8_10 +7

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:70498
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:70459
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:70498
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:70402
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:70459
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:70402
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:70498
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:70459
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:70403
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:70403
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:70498
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:70459
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:70498
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:70459
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-45894
  2. 2026-10-03 Alias added: GHSA-8pm8-q9qq-gqgp
  3. 2026-10-16 CISA SSVC decision points changed
  4. 2026-10-19 Weakness changed · CISA ADP
  5. 2026-10-21 Fix available: Linux/[email protected], Linux/Linux@c36b0515c6445bd137ec8ad86ef5470c45d6e4bf · CNA
  6. 2026-10-21 1 new reference · CNA
  7. 2026-10-30 Fix available: Linux/[email protected], Linux/Linux@bed36f5657d34ae982d48045a75bff6113790cf9 · CNA
  8. 2026-10-30 1 new reference · CNA
  9. 2026-11-06 CVSS score changed · Red Hat

References

Patch 4

Other 2

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences