CVE-2026-90240

iommu/vt-d: Flush context cache with correct SID when tearing down aliases

Published Sep 17, 2026 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

iommu/vt-d: Flush context cache with correct SID when tearing down aliases

domain_context_clear_one() and device_pasid_table_teardown() are both
invoked once per DMA alias of a device. Each function locates the context
entry using the bus/devfn pair provided by the pci_for_each_dma_alias()
callback, then calls intel_context_flush_no_pasid(), which constructs a
device-selective context-cache invalidation from info->bus and
info->devfn (that is, always the requester ID of the device itself).

As a result, for every alias other than the device’s own RID, the context
entry that was just cleared in memory is never invalidated in the context
cache. Hardware may continue using that stale cached entry. In the
scalable-mode teardown path, intel_pasid_free_table() can then free the
PASID directory still referenced by that stale entry, allowing the IOMMU
to walk freed memory.

Fix this by passing the source ID of the entry being torn down to
intel_context_flush_no_pasid(), instead of deriving it from @info.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4904-1 linux-6.12 security update
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-416
Type Values Removed Values Added
Weaknesses CWE-411
Type Values Removed Values Added
Weaknesses CWE-411
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'}

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Flush context cache with correct SID when tearing down aliases domain_context_clear_one() and device_pasid_table_teardown() are both invoked once per DMA alias of a device. Each function locates the context entry using the bus/devfn pair provided by the pci_for_each_dma_alias() callback, then calls intel_context_flush_no_pasid(), which constructs a device-selective context-cache invalidation from info->bus and info->devfn (that is, always the requester ID of the device itself). As a result, for every alias other than the device’s own RID, the context entry that was just cleared in memory is never invalidated in the context cache. Hardware may continue using that stale cached entry. In the scalable-mode teardown path, intel_pasid_free_table() can then free the PASID directory still referenced by that stale entry, allowing the IOMMU to walk freed memory. Fix this by passing the source ID of the entry being torn down to intel_context_flush_no_pasid(), instead of deriving it from @info.
Title iommu/vt-d: Flush context cache with correct SID when tearing down aliases
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 21, 2026, 12:50 PM
Reserved
Sep 11, 2026, 7:38 PM
Status
Received
Published
Sep 17, 2026, 5:17 PM
Modified
Oct 21, 2026, 1:20 PM