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 19804.0.0

medium Tenable Cloud Security Plugin ID 470062

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/efi: Fix graceful fault handling
after FPU softirq changes Since commit d02198550423 ("x86/fpu: Improve crypto performance by making
kernel-mode FPU reliably usable in softirqs"), kernel_fpu_begin() calls fpregs_lock() which uses
local_bh_disable() instead of the previous preempt_disable(). This sets SOFTIRQ_OFFSET in preempt_count
during the entire EFI runtime service call, causing in_interrupt() to return true in normal task context.
The graceful page fault handler efi_crash_gracefully_on_page_fault() uses in_interrupt() to bail out for
faults in real interrupt context. With SOFTIRQ_OFFSET now set, the handler always bails out, leaving EFI
firmware page faults unhandled. This escalates to die() which also sees in_interrupt() as true and calls
panic("Fatal exception in interrupt"), resulting in a hard system freeze. On systems with buggy firmware
that triggers page faults during EFI runtime calls (e.g., accessing unmapped memory in GetTime()), this
causes an unrecoverable hang instead of the expected graceful EFI_ABORTED recovery. Fix by replacing
in_interrupt() with !in_task(). This preserves the original intent of bailing for interrupts or NMI
faults, while no longer falsely triggering from the FPU code path's local_bh_disable(). [ardb: Sashiko
spotted that using 'in_hardirq() || in_nmi()' leaves a window where a softirq may be taken before
fpregs_lock() is called, but after efi_rts_work.efi_rts_id has been assigned, and any page faults
occurring in that window will then be misidentified as having been caused by the firmware. Instead, use
!in_task(), which incorporates in_serving_softirq(). ] (CVE-2026-46290)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 19804.0.0 or later.

Plugin Details

Severity: Medium

ID: 470062

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: 23.75

Vendor

Vendor Severity: MEDIUM

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-2026-46290

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: 5/26/2026

Reference Information

CVE: CVE-2026-46290

Detections

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