Google: sys-kernel/cchost-kernel-6_12, sys-kernel/csql-kernel-6_12, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_12: security update to 19506.120.97

medium Tenable Cloud Security Plugin ID 469550

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

- In the Linux kernel, the following vulnerability has been resolved: arm64: contpte: fix set_access_flags()
no-op check for SMMU/ATS faults contpte_ptep_set_access_flags() compared the gathered ptep_get() value
against the requested entry to detect no-ops. ptep_get() ORs AF/dirty from all sub-PTEs in the CONT block,
so a dirty sibling can make the target appear already-dirty. When the gathered value matches entry, the
function returns 0 even though the target sub-PTE still has PTE_RDONLY set in hardware. For a CPU with
FEAT_HAFDBS this gathered view is fine, since hardware may set AF/dirty on any sub-PTE and CPU TLB
behavior is effectively gathered across the CONT range. But page-table walkers that evaluate each
descriptor individually (e.g. a CPU without DBM support, or an SMMU without HTTU, or with HA/HD disabled
in CD.TCR) can keep faulting on the unchanged target sub-PTE, causing an infinite fault loop. Gathering
can therefore cause false no-ops when only a sibling has been updated: - write faults: target still has
PTE_RDONLY (needs PTE_RDONLY cleared) - read faults: target still lacks PTE_AF Fix by checking each sub-
PTE against the requested AF/dirty/write state (the same bits consumed by __ptep_set_access_flags()),
using raw per-PTE values rather than the gathered ptep_get() view, before returning no-op. Keep using the
raw target PTE for the write-bit unfold decision. Per Arm ARM (DDI 0487) D8.7.1 ("The Contiguous bit"),
any sub-PTE in a CONT range may become the effective cached translation and software must maintain
consistent attributes across the range. (CVE-2026-43486)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19506.120.97 or later.

Plugin Details

Severity: Medium

ID: 469550

Version: Revision 1.6

Type: Local

Family: Google COS Security Checks

Published: 10/3/2026

Updated: 10/6/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.71

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C

CVSS Score Source: CVE-2026-43486

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 4/30/2026

Reference Information

CVE: CVE-2026-43486

Detections

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