Google: sys-kernel/cchost-kernel-6_12, sys-kernel/csql-kernel-6_12, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_12: security update to 19506.505.8

high Tenable Self-Hosted Container Security Plugin ID 470339

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: bpf: Harden bloom filter sizing and
indexing on 32-bit kernels bloom_map_alloc() has two 32-bit-specific problems when the computed bitmap
reaches the U32_MAX fallback case. First, BITS_TO_BYTES(U32_MAX) is evaluated with 32-bit arithmetic. The
addition performed by DIV_ROUND_UP wraps, so the map allocates only the fixed-size bloom filter object
while keeping bitset_mask == U32_MAX. Subsequent updates can then write past the allocated object. Second,
fixing only the allocation size is not sufficient. The bloom hash is a u32, but set_bit() takes a signed
long bit number and x86 test_bit() eventually feeds the index to variable_test_bit(long, ...). On 32-bit
kernels, hashes in [0x80000000, U32_MAX] therefore become negative bit offsets. x86 bt/bts with a memory
operand interpret those offsets relative to the supplied base, so a map with bitset_mask == U32_MAX can
read or write before bloom->bitset even after allocating the full 512 MiB bitmap. Keep the U32_MAX
fallback, but split each hash into a word pointer and an in-word bit number before calling test_bit() or
set_bit(). The bitops argument is then always in [0, BITS_PER_LONG - 1], while BIT_WORD(h) still selects
the intended word in the full bitmap. Compute the bitset size from (u64)bitset_mask + 1 before passing the
final size to bpf_map_area_alloc(). This fixes the original under-allocation and keeps the allocated
storage consistent with the addressable bitset. Exploitation note: local privilege escalation is possible
on a 32-bit x86 kernel using the under-allocation bug from a binary with CAP_BPF. (CVE-2026-89579)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19506.505.8 or later.

Plugin Details

Severity: High

ID: 470339

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: Medium

Score: 4.9

Percentile: 58.22

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-2026-89579

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: 9/11/2026

Reference Information

CVE: CVE-2026-89579

Detections

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