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 20098.0.0

high Tenable Cloud Security Plugin ID 471448

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: io_uring/rsrc: fix folio size overflow
in io_vec_fill_bvec() io_vec_fill_bvec() computes the folio size with a plain int 1: unsigned long
folio_size = 1 << imu->folio_shift; imu->folio_shift is unsigned int and comes from folio_shift() of the
folio backing the registered buffer, so it can be 32 or more on a 64 bit kernel. Shifting int 1 that far
is undefined, and on x86 and arm64 the count is taken modulo 32, so a shift of 34 yields 4 rather than
16G. Every other folio_shift shift in this file already uses 1UL. The result is that the segment estimate
and the fill loop disagree. io_estimate_bvec_size() sizes the bvec array with the real shift: max_segs +=
(iov[i].iov_len >> shift) + 2; so a 1M iovec on a 16G folio is charged 2 segments, while
io_vec_fill_bvec() then walks the same iovec in folio_size chunks of 4 bytes and writes res_bvec[bvec_idx]
a quarter of a million times, past the end of the array it was given. src_bvec is advanced once per
iteration as well, so imu->bvec is read past its end at the same time. validate_fixed_range() only checks
that the range is inside the registered buffer and does not bound the segment count. Reaching it needs a
folio with a shift of at least 32, which means a gigantic hugetlb page: 16G on arm64 with 64K pages, where
CONT_PMD_SHIFT is 34 and hugetlb_add_hstate(CONT_PMD_SHIFT - PAGE_SHIFT) registers that size, and likewise
on powerpc. x86_64 tops out at 1G, so a shift of 30, which still fits in int and is unaffected. Use 1UL,
as the rest of the file does. (CVE-2026-80810)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 20098.0.0 or later.

Plugin Details

Severity: High

ID: 471448

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: Medium

Score: 4.3

Percentile: 53.48

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Medium

Base Score: 6.6

Temporal Score: 4.9

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

CVSS Score Source: CVE-2026-80810

CVSS v3

Risk Factor: High

Base Score: 7.1

Temporal Score: 6.2

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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: 9/4/2026

Reference Information

CVE: CVE-2026-80810

Detections

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