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

high Tenable Cloud Security Plugin ID 475318

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: mm/mm_init: deferred_grow_zone(): fix
out-of-range first_deferred_pfn With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, deferred_grow_zone()
initializes struct pages early in boot to satisfy an allocation. With a large CMA reservation in place,
the ranges deferred_init_memmap() finds may not add up to the allocation it was asked for, and the
function ends up initializing the memory map of the entire zone and still falls short. That is fine in
itself: the function accounts for it and leaves the caller to decide whether it now has enough memory.
However, the update of pgdat->first_deferred_pfn that tracks where uninitialized memory map starts could
overflow. If the node's RAM end is not aligned on PAGES_PER_SECTION boundaries and some deferred struct
pages were initialized, pgdat->first_deferred_pfn would point past the end of the node's memory.
deferred_init_memmap() later picks up from pgdat->first_deferred_pfn and hits a BUG_ON(), because it
expects a pfn within its node. For example, when running a kernel with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
and CONFIG_CMA=y using the following qemu command line qemu-system-x86_64 -enable-kvm -m 8032M -kernel
bzImage \ -append "nokaslr cma=4768M@0x100000000" the kernel panics: kernel BUG at mm/mm_init.c:2131! CPU:
3 UID: 0 PID: 36 Comm: pgdatinit0 Not tainted 7.2.0-rc6 #1 RIP: 0010:deferred_init_memmap+0x1b8/0x1c0 RAX:
0000000000236000 R13: 0000000000238000 Call Trace: kthread+0xdf/0x120 ret_from_fork+0x187/0x250 Make sure
that the update of pgdta->first_deferred_pfn does not overflow when the entire zone's (and therefore
node's) memory map is initialized. [rppt: massaged the changelog] (CVE-2026-93227)

Solution

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

Plugin Details

Severity: High

ID: 475318

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/16/2026

Updated: 10/16/2026

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.34

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

CVSS Score Source: CVE-2026-93227

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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: 9/24/2026

Reference Information

CVE: CVE-2026-93227

Detections

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