CVE-2026-45894iommu/vt-d: Clear Present bit before tearing down PASID entry
- 7.8HighCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 97% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By Linux
- 14 days later
· 14 days later
Published
- 5 months later
· 5 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.13% · top 97% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15 – < bed36f5657d34ae982d48045a75bff6113790cf9
- affected 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15 – < c36b0515c6445bd137ec8ad86ef5470c45d6e4bf
- affected 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15 – < a84d30e8d2bacd21782a6481158b7c9c552f4868
- affected 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15 – < 821807c167b7b48a41b95b6607c6b9f97600f7d9
- affected 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15 – < 949d71666e9dd19f21e7b4b53a88cd2c5b902858
- affected 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15 – < 75ed00055c059dedc47b5daaaa2f8a7a019138ff
- affected 5.0
- unaffected < 5.0
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.75 – ≤ 6.12.*
- unaffected 6.18.14 – ≤ 6.18.*
- unaffected 6.19.4 – ≤ 6.19.*
- unaffected 7.0 – ≤ *
References
References6
- https://git.kernel.org/stable/c/bed36f5657d34ae982d48045a75bff6113790cf9 (opens in a new tab)
- https://git.kernel.org/stable/c/c36b0515c6445bd137ec8ad86ef5470c45d6e4bf (opens in a new tab)
- https://git.kernel.org/stable/c/a84d30e8d2bacd21782a6481158b7c9c552f4868 (opens in a new tab)
- https://git.kernel.org/stable/c/821807c167b7b48a41b95b6607c6b9f97600f7d9 (opens in a new tab)
- https://git.kernel.org/stable/c/949d71666e9dd19f21e7b4b53a88cd2c5b902858 (opens in a new tab)
- https://git.kernel.org/stable/c/75ed00055c059dedc47b5daaaa2f8a7a019138ff (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-32360 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-45894)Record last updated .