Google: sys-kernel/csql-kernel-6_1, sys-kernel/csql-kernel-6_6, sys-kernel/lakitu-kernel-6_1, sys-kernel/lakitu-kernel-6_6, sys-kernel/lakitu-nc-kernel-6_6, sys-kernel/lakitu-vgpu-kernel-6_6, sys-kernel/tpusev-kernel-6_6: security update to 18613.675.56

high Tenable Cloud Security Plugin ID 466348

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: iommu/amd: Wait for completion instead
of returning early in iommu_completion_wait() need_sync is a per-IOMMU flag shared by all domains and
devices behind that IOMMU. It is set whenever a command is queued with sync == true and cleared when a
completion-wait (CWAIT) command is queued. However, a cleared need_sync only means that a covering CWAIT
has been queued, not that all previously queued commands have actually completed in hardware.
iommu_completion_wait() read need_sync locklessly and returned early when it was false. This breaks the
"block until all previously queued commands have completed" contract in a multi-CPU scenario: CPU2: queue
inv-B => need_sync = true CPU1: queue CWAIT(N); need_sync = false; then wait_on_sem(N) CPU2: read
need_sync == false => return 0 (no wait!) CPU2 returns without waiting for any sequence number even though
its inv-B may not have completed yet (CWAIT(N), queued after inv-B, has not been signaled). CPU2 then
proceeds to, for example, free page-table pages while the IOMMU can still walk stale translations, opening
a use-after-free window. This is a logical race in the meaning of the flag, not a memory-visibility issue,
so barriers alone do not help. Fix it without losing the optimization of avoiding redundant CWAIT
commands: take iommu->lock before testing need_sync, and when it is false do not return early but wait for
the last allocated sequence number (cmd_sem_val). Since need_sync == false implies no sync command was
queued after the last CWAIT, that CWAIT is FIFO-ordered after every not-yet-completed command, so waiting
for its sequence number guarantees all prior commands (possibly queued by another CPU) have completed. The
common path with pending work is unchanged and no extra hardware command is issued. (CVE-2026-68329)

Solution

Update the sys-kernel/csql-kernel-6_1 library and its related packages to version 18613.675.56 or later.

Plugin Details

Severity: High

ID: 466348

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: High

Score: 7

Percentile: 98.11

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-2026-68329

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/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: 8/10/2026

Reference Information

CVE: CVE-2026-68329

Detections

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