GHSA-8pm8-q9qq-gqgp · Severity: high — In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Clear Present...
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.
Conclusion & alert: CVE-2026-45894 is rated Low Risk (32.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-28 | — | 0.02% | — |
Full EPSS history (1 record total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.8 | 3.1 | HIGH |
|
1.1 | 6.0 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
GHSA-8pm8-q9qq-gqgp · Severity: high — In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Clear Present...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2026-45894 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. | https://security-tracker.debian.org/tracker/CVE-2026-45894 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2026-45894 |
suse
|
high | — | https://www.suse.com/security/cve/CVE-2026-45894/ |
ubuntu
|
medium | CVE-2026-45894 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 891 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 508, needs-triage 224, ignored 159. | https://ubuntu.com/security/CVE-2026-45894 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| No affected products in dataset. | |||