CVE-2026-89450: Linux kernel · iommu/tegra241-cmdqv: Reject a vSID wider than the SID_MATCH field
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 28 Oct 2026, 01:00 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: iommu/tegra241-cmdqv: Reject a vSID wider than the SID_MATCH field tegra241_vintf_init_vsid() programs the guest-provided vSID into SID_MATCH, whose VIRT_SID field spans bits [20:1] with bit 0 as the match-enable flag. The HW therefore matches only a 20-bit Stream ID. The bound check rejects only virt_sid > UINT_MAX, which admits a value far wider than the field. The write "virt_sid << 1 | 0x1" then drops every bit above 20: a virt_sid of 0x80000000 lands as SID_MATCH = 0x1, a valid match on vSID 0, so the entry aliases the wrong Stream ID. Because vdev->virt_id is guest-controlled, a VMM can trigger it. Validate virt_sid against the field width with FIELD_MAX(), and program the register with FIELD_PREP() so the value and the field stay consistent.
References
- ubuntu.com/security/CVE-2026-89450 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89450 (opens in a new tab)
- git.kernel.org/linus/4379610c79bd88ddbea10e7f6c21e16d4b338c6b (opens in a new tab)
- git.kernel.org/stable/c/4379610c79bd88ddbea10e7f6c21e16d4b338c6b (opens in a new tab)
- git.kernel.org/stable/c/445204550f894ca325ac80a21e3df177ad073798 (opens in a new tab)
- git.kernel.org/stable/c/d903d99ffd22b0180bd745a43f221c21bcdd8d7c (opens in a new tab)