Linux Kernel up to 6.12.109/6.18.51/7.2.5 iommu-vt-d copied_context_tear_down race condition

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k0.00+

Summaryinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.12.109/6.18.51/7.2.5. This affects the function copied_context_tear_down of the component iommu-vt-d. This manipulation causes race condition. This vulnerability is handled as CVE-2026-90243. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.109/6.18.51/7.2.5. It has been declared as very critical. Affected by this vulnerability is the function copied_context_tear_down of the component iommu-vt-d. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Clear Present bit before tearing down copied context entry copied_context_tear_down() zeroes the 128-bit context entry with context_clear_entry() while the Present bit is still set, and only then issues the context-cache and IOTLB invalidations. This leaves a window in which hardware can fetch a torn entry, with some fields already zeroed while Present is still set, leading to unpredictable behaviour or spurious faults. While x86 provides strong write ordering, the compiler may reorder the writes to the two 64-bit halves of the entry, and the hardware fetch is not guaranteed to be atomic with respect to multiple CPU writes. There is no cacheline flush before the invalidation either, so on an IOMMU without coherent access to the context table the zeroed entry may not be visible to hardware at the point the invalidation is submitted. Apply the same ownership handshake described in the VT-d spec, Section 6.5.3.3 ("Guidance to Software for Invalidations"): clear only the Present bit, flush it out to the IOMMU, perform the invalidations, and only then zero the remainder of the entry.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-90243 since 09/11/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/17/2026).

Upgrading to version 6.12.110, 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch 97750a8dce79c1a9b2b2d2a020b61b800141996c/3c88cfedc7768b1ae2dc7ddc71547ae9a1aaff7d/6b822d18c33af9d1e16a8e5e6aa6e656987b09de/f532c57985b1a7d6b7e37e05506b46d413e5cca4 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: 97750a8dce79c1a9b2b2d2a020b61b800141996c/3c88cfedc7768b1ae2dc7ddc71547ae9a1aaff7d/6b822d18c33af9d1e16a8e5e6aa6e656987b09de/f532c57985b1a7d6b7e37e05506b46d413e5cca4

Timelineinfo

09/11/2026 CVE reserved
09/17/2026 +6 days Advisory disclosed
09/17/2026 +0 days VulDB entry created
09/17/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-90243 (🔒)
GCVE (CVE): GCVE-0-2026-90243
GCVE (VulDB): GCVE-100-406771

Entryinfo

Created: 09/17/2026 21:04
Changes: 09/17/2026 21:04 (59)
Complete: 🔍
Cache ID: 216::103

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