Google: sys-kernel/cchost-kernel-6_18, sys-kernel/csql-kernel-6_18, sys-kernel/lakitu-kernel-6_18, sys-kernel/lakitu-nc-kernel-6_18: security update to 19999.44.106

medium Tenable Cloud Security Plugin ID 475334

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: dm-io: clone the source bio instead of
copying its biovec For DM_IO_BIO requests, do_region() built each destination bio by walking the source
bio's biovec and re-adding the pages one at a time, tracking the remaining transfer in sectors. The vector
lengths are byte granular and need not be sector aligned (e.g. a misaligned O_DIRECT buffer split across
pages), so the sector-based accounting could lose a sub-sector fragment: to_sector() truncated the
remainder and the outer loop spun forever submitting empty bios, hanging the I/O. There is no need to
rebuild the biovec at all. The destination reads into (or writes from) exactly the same pages as the
source bio, so the bio can simply clone the source's biovec with bio_alloc_clone() and remap it to the
target device. The clone inherits the source's iterator and alignment, and the block layer splits it to
the target's limits on submission, so the whole region maps to a single cloned bio with no manual page
copying or sector accounting. This removes the per-page copy path (and its open-coded bvec dpages helpers)
for bio-backed I/O and fixes the hang on misaligned direct I/O to a dm-mirror device. Page-list, vma and
kmem sources keep the existing copy path. (CVE-2026-89578)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 19999.44.106 or later.

Plugin Details

Severity: Medium

ID: 475334

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/16/2026

Updated: 10/16/2026

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.66

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Medium

Base Score: 4.9

Temporal Score: 3.6

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

CVSS Score Source: CVE-2026-89578

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: 9/11/2026

Reference Information

CVE: CVE-2026-89578

Detections

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