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 20085.0.0

critical Tenable Cloud Security Plugin ID 472198

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: KVM: x86/mmu: WARN and clear
role.invalid when creating a child shadow page Explicitly clear role.invalid when deriving a child shadow
page's role from its parent to harden against bugs elsewhere in KVM, as violating KVM's invariant that
invalid pages are NOT on the list of active MMU pages leads to use-after-free due to
__kvm_mmu_prepare_zap_page() using list_add() instead of list_move() when processing an invalid shadow
page, i.e. makes a bad situation far worse. Yell loudly if the parent is invalid, as it means KVM has
missed a validity check, i.e. KVM is attempting to map memory using an invalid/obsolete root, but continue
on as the child is otherwise still a valid shadow page.
================================================================== BUG: KASAN: slab-use-after-free in
__kvm_mmu_get_shadow_page+0x1817/0x1860 [kvm] Write of size 8 at addr ff11000153dd1368 by task repro/853
CPU: 1 UID: 1000 PID: 853 Comm: repro Not tainted 7.2.0-rc2-3aec122bdcaf-next-vm #5 PREEMPT Hardware name:
QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: <TASK> dump_stack_lvl+0x4b/0x70
print_report+0x153/0x49c kasan_report+0xbc/0xf0 __kvm_mmu_get_shadow_page+0x1817/0x1860 [kvm]
mmu_alloc_root+0x141/0x320 [kvm] kvm_mmu_load+0x612/0x20f0 [kvm] kvm_arch_vcpu_ioctl_run+0x3dd5/0x6150
[kvm] kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm] __x64_sys_ioctl+0x131/0x1b0 do_syscall_64+0x67/0x5f0
entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> Allocated by task 853: kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30 __kasan_slab_alloc+0x5f/0x70 kmem_cache_alloc_noprof+0xfe/0x2e0
__kvm_mmu_topup_memory_cache+0x135/0x530 [kvm] paging64_page_fault+0x318/0x1e30 [kvm]
kvm_mmu_do_page_fault+0x21d/0x630 [kvm] kvm_mmu_page_fault+0x18c/0x17b0 [kvm]
kvm_arch_vcpu_ioctl_run+0x1f35/0x6150 [kvm] kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm] __x64_sys_ioctl+0x131/0x1b0
do_syscall_64+0x67/0x5f0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Freed by task 853:
kasan_save_stack+0x20/0x40 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x43/0x70 kmem_cache_free+0xe2/0x400 kvm_mmu_commit_zap_page.part.0+0x1e2/0x310 [kvm]
kvm_mmu_free_roots+0x283/0x560 [kvm] kvm_arch_vcpu_ioctl_run+0x33c8/0x6150 [kvm]
kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm] __x64_sys_ioctl+0x131/0x1b0 do_syscall_64+0x67/0x5f0
entry_SYSCALL_64_after_hwframe+0x4b/0x53 (CVE-2026-80726)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 20085.0.0 or later.

Plugin Details

Severity: Critical

ID: 472198

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/3/2026

Updated: 10/3/2026

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 93.46

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

CVSS Score Source: CVE-2026-80726

CVSS v3

Risk Factor: Critical

Base Score: 9.3

Temporal Score: 8.1

Vector: CVSS:3.0/AV:L/AC:L/PR:N/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: 9/3/2026

Reference Information

CVE: CVE-2026-80726

Detections

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