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 475473

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: x86/mm/pat: Acquire init_mm write lock
on collapse to avoid UAF x86 implements page attribute modification using its Change Page Attributes (CPA)
mechanism. This tracks properties of ranges such as cache mode through x86 page attributes, and as part of
that logic manipulates kernel page tables. Since commit: 41d88484c71c ("x86/mm/pat: restore large ROX
pages after fragmentation") ranges of kernel page table entries can be collapsed into huge page table
entries as part of this logic. As part of this collapse, it frees the page tables which the collapsed
entries previously pointed to, and it does so without any relevant locks being held to preclude concurrent
kernel page table walkers. The only way this code can be reached is if CPA_COLLAPSE is specified, and this
is only set in set_memory_rox() via: set_memory_rox() -> change_page_attr_set_clr() -> cpa_flush() ->
cpa_collapse_large_pages() Notable users of this are execmem and BPF when manipulating executable
mappings. However, this is problematic for ptdump as it walks ranges it does not own and thus runs the
risk of a use-after-free on page tables freed underneath it. In addition, concurrent CPA collapse
operations are possible which can also cause races. Resolve the issue by acquiring the mmap write lock on
init_mm across the whole operation. It is safe to acquire a sleeping lock as all the callers invoke
set_memory_rox() from process context and in any case, change_page_attr_set_clr() calls vm_unmap_alias()
which ultimately takes a mutex, disallowing atomic context here. (CVE-2026-97943)

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: 475473

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: 4.3

Percentile: 53.43

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Medium

Base Score: 5.6

Temporal Score: 4.1

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

CVSS Score Source: CVE-2026-97943

CVSS v3

Risk Factor: High

Base Score: 7.1

Temporal Score: 6.2

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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: 9/25/2026

Reference Information

CVE: CVE-2026-97943

Detections

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