In the Linux kernel, the following vulnerability has been resolved:
iommupt: Fix short gather if the unmap goes into a large mapping
unmap has the odd behavior that it can unmap more than requested if the
ending point lands within the middle of a large or contiguous IOPTE.
In this case the gather should flush everything unmapped which can be
larger than what was requested to be unmapped. The gather was only
flushing the range requested to be unmapped, not extending to the extra
range, resulting in a short invalidation if the caller hits this special
condition.
This was found by the new invalidation/gather test I am adding in
preparation for ARMv8. Claude deduced the root cause.
As far as I remember nothing relies on unmapping a large entry, so this is
likely not a triggerable bug.
iommupt: Fix short gather if the unmap goes into a large mapping
unmap has the odd behavior that it can unmap more than requested if the
ending point lands within the middle of a large or contiguous IOPTE.
In this case the gather should flush everything unmapped which can be
larger than what was requested to be unmapped. The gather was only
flushing the range requested to be unmapped, not extending to the extra
range, resulting in a short invalidation if the caller hits this special
condition.
This was found by the new invalidation/gather test I am adding in
preparation for ARMv8. Claude deduced the root cause.
As far as I remember nothing relies on unmapping a large entry, so this is
likely not a triggerable bug.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 01 May 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: iommupt: Fix short gather if the unmap goes into a large mapping unmap has the odd behavior that it can unmap more than requested if the ending point lands within the middle of a large or contiguous IOPTE. In this case the gather should flush everything unmapped which can be larger than what was requested to be unmapped. The gather was only flushing the range requested to be unmapped, not extending to the extra range, resulting in a short invalidation if the caller hits this special condition. This was found by the new invalidation/gather test I am adding in preparation for ARMv8. Claude deduced the root cause. As far as I remember nothing relies on unmapping a large entry, so this is likely not a triggerable bug. | |
| Title | iommupt: Fix short gather if the unmap goes into a large mapping | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-01T14:14:32.923Z
Reserved: 2026-03-09T15:48:24.137Z
Link: CVE-2026-31735
No data.
Status : Awaiting Analysis
Published: 2026-05-01T15:16:36.140
Modified: 2026-05-01T15:24:14.893
Link: CVE-2026-31735
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.