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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.19 | 6.19.12 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.19.12-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | linux-nvidia | 7.0.0-1006.6 | — |
| Ubuntu 24.04 LTS | linux-riscv +15 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | No fix yet | — |
Advisories 1
- WID-SEC-2026-1346 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026