Google: sys-kernel/cchost-kernel-6_12, sys-kernel/csql-kernel-6_12, sys-kernel/csql-kernel-6_6, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-kernel-6_6, sys-kernel/lakitu-nc-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_6, sys-kernel/lakitu-vgpu-kernel-6_6: security update to 19216.532.3

high Tenable Self-Hosted Container Security Plugin ID 469268

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: hv_netvsc: use kmap_local_page in
netvsc_copy_to_send_buf netvsc_copy_to_send_buf() copies page buffer entries into the VMBus send buffer
using phys_to_virt() on the entry PFN. Entries for the RNDIS header and the skb linear data come from
kmalloc'd memory and are always in the kernel direct map, but entries for skb fragments reference page
cache or user pages, which on 32-bit x86 with CONFIG_HIGHMEM=y can live above the LOWMEM boundary. For
such a page phys_to_virt() returns an address outside the direct map and the subsequent memcpy() faults on
the transmit softirq path, which is fatal. Map the pages with kmap_local_page() instead, handling two
properties of the page buffer entries: - pb[i].pfn is a Hyper-V PFN at HV_HYP_PAGE_SIZE (4K) granularity,
not a native PFN. Reconstruct the physical address first and derive the native page from it, so the
mapping stays correct where PAGE_SIZE > HV_HYP_PAGE_SIZE (e.g. arm64 with 64K pages). - Since commit
41a6328b2c55 ("hv_netvsc: Preserve contiguous PFN grouping in the page buffer array"), an entry describes
a full physically contiguous fragment and pb[i].len can exceed PAGE_SIZE, while kmap_local_page() maps a
single page. Copy page by page, splitting at native page boundaries. The copy path only handles packets
smaller than the send section size (6144 bytes by default); larger packets take the cp_partial path where
only the RNDIS header is copied. So entries here are bounded by the section size and a copy is split at
most once on 4K-page systems. On !CONFIG_HIGHMEM configs kmap_local_page() folds to page_address() and no
mapping work is added. (CVE-2026-53199)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19216.532.3 or later.

Plugin Details

Severity: High

ID: 469268

Version: Revision 1.5

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: HIGH

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-53199

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/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: 6/25/2026

Reference Information

CVE: CVE-2026-53199

Detections

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