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 20198.0.0

high Tenable Cloud Security Plugin ID 475586

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: btrfs: tree-checker: validate
INODE_REF's namelen [BUG] A crafted btrfs image can trigger the following crash: BUG: unable to handle
page fault for address: ffffd1dc42884000 #PF: supervisor write access in kernel mode #PF:
error_code(0x0002) - not-present page CPU: 9 UID: 0 PID: 1034 Comm: poc Not tainted 7.1.0-rc4-custom+ #383
PREEMPT(full) 46af0a92938a63be7132e0dfd71e62327c51d5c2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
BIOS unknown 02/02/2022 RIP: 0010:memcpy+0xc/0x10 Call Trace: <TASK> read_extent_buffer+0xe4/0x100 [btrfs
3cf0785dd58fec8c5ff84633b772f17ce1f92a8f] btrfs_get_name+0x15e/0x1e0 [btrfs
3cf0785dd58fec8c5ff84633b772f17ce1f92a8f] reconnect_path+0x165/0x390 exportfs_decode_fh_raw+0x337/0x400 ?
drop_caches_sysctl_handler+0xb0/0xb0 </TASK> ---[ end trace 0000000000000000 ]--- RIP:
0010:memcpy+0xc/0x10 Kernel panic - not syncing: Fatal exception [CAUSE] TThe crafted image has the
following corrupted INODE_REF item: item 9 key (258 INODE_REF 257) itemoff 11544 itemsize 4106 index 2
namelen 4096 name: d\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\0
00\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000
\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\0
00\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000
\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\0
00\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000
\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\0
00\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000
\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\0
00\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000 The itemsize matches
the namelen, but the namelen is 4096, way larger than normal name length limit (BTRFS_NAME_LEN, 255).
Meanwhile the memory of the @name is only 255 byte sized, this will cause out-of-boundary access, and
cause the above crash. [FIX] Add extra namelen verification for INODE_REF, just like what we have done in
ROOT_REF checks. Now the crafted image can be rejected gracefully: BTRFS critical (device dm-2): corrupt
leaf: root=5 block=30572544 slot=14 ino=259, invalid inode ref name length, has 4096 expect [1, 255] BTRFS
error (device dm-2): read time tree block corruption detected on logical 30572544 mirror 2 [ Rebase, add a
Link: tag, add an simple cause analyze ] (CVE-2026-93813)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 20198.0.0 or later.

Plugin Details

Severity: High

ID: 475586

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/16/2026

Updated: 10/16/2026

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.42

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-2026-93813

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: 9/24/2026

Reference Information

CVE: CVE-2026-93813

Detections

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