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 470457

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: sched_ext: Fix starvation of
scx_enable() under fair-class saturation During scx_enable(), the READY -> ENABLED task switching loop
changes the calling thread's sched_class from fair to ext. Since fair has higher priority than ext,
saturating fair-class workloads can indefinitely starve the enable thread, hanging the system. This was
introduced when the enable path switched from preempt_disable() to scx_bypass() which doesn't protect
against fair-class starvation. Note that the original preempt_disable() protection wasn't complete either
- in partial switch modes, the calling thread could still be starved after preempt_enable() as it may have
been switched to ext class. Fix it by offloading the enable body to a dedicated system-wide RT
(SCHED_FIFO) kthread which cannot be starved by either fair or ext class tasks. scx_enable() lazily
creates the kthread on first use and passes the ops pointer through a struct scx_enable_cmd containing the
kthread_work, then synchronously waits for completion. The workfn runs on a different kthread from
sch->helper (which runs disable_work), so it can safely flush disable_work on the error path without
deadlock. (CVE-2026-43392)

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: 470457

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: 23.72

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-2026-43392

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-2026-43392

Detections

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