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 20085.0.0

high Tenable Cloud Security Plugin ID 470892

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: ring-buffer: Use current_context for
safe per-CPU buffer swap The ring_buffer_swap_cpu() function currently checks the per-CPU committing
counter to determine if a buffer is actively being written to before performing the swap. However, there
exists a race window where this check can be bypassed: ring_buffer_lock_reserve cpu_buffer =
buffer->buffers[cpu]; // cpu_buffer_a rb_reserve_next_event rb_start_commit // inc committing if
(unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) {...} __rb_reserve_next rb_move_tail
rb_end_commit(cpu_buffer); // dec committing => 0 /* interrupt hits here, successfully swaps! */
local_inc(&cpu_buffer->committing); ring_buffer_unlock_commit cpu_buffer = buffer->buffers[cpu]; //
cpu_buffer_b rb_commit rb_end_commit RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing)) //
triggers warning The committing counter can temporarily drop to 0 during a single write operation (within
rb_move_tail), creating a window where swap can succeed even though the write is still in progress. This
leads to inconsistent buffer state and triggers the RB_WARN_ON in rb_commit(). Replace the committing
counter check with current_context checks, which are set at the entry of ring_buffer_lock_reserve() and
remain valid throughout the entire write operation, providing a reliable indicator of buffer busy state
during swap. (CVE-2026-74601)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 20085.0.0 or later.

Plugin Details

Severity: High

ID: 470892

Version: Revision 1.3

Type: Local

Family: Google COS Security Checks

Published: 10/3/2026

Updated: 10/3/2026

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

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.35

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-74601

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: 8/22/2026

Reference Information

CVE: CVE-2026-74601

Detections

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