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

medium Tenable Cloud Security Plugin ID 475788

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: balance: fix potential bg
lookup failure in btrfs_may_alloc_data_chunk() [BUG] Running btrfs balance can trigger a null-ptr-deref
before relocating a data chunk when metadata corruption leaves a chunk in the chunk tree without a
corresponding block group in the in-memory cache: KASAN: null-ptr-deref in range
[0x0000000000000088-0x000000000000008f] RIP: 0010:btrfs_may_alloc_data_chunk+0x40/0x1c0
fs/btrfs/volumes.c:3601 Call Trace: __btrfs_balance fs/btrfs/volumes.c:4217 [inline]
btrfs_balance+0x2516/0x42b0 fs/btrfs/volumes.c:4604 btrfs_ioctl_balance fs/btrfs/ioctl.c:3577 [inline]
btrfs_ioctl+0x25cf/0x5b90 fs/btrfs/ioctl.c:5313 ... [CAUSE] __btrfs_balance() iterates the on-disk chunk
tree and passes the chunk logical bytenr to btrfs_may_alloc_data_chunk() before relocating a data chunk.
That helper then queries the in-memory block group cache: cache = btrfs_lookup_block_group(fs_info,
chunk_offset); chunk_type = cache->flags; /* cache may be NULL */ A corrupt image can contain a chunk item
whose matching block group item is missing, so no block group is ever inserted into the cache. In that
case btrfs_lookup_block_group() returns NULL. The code only guards this with ASSERT(cache), which becomes
a no-op when CONFIG_BTRFS_ASSERT is disabled. The subsequent dereference of cache->flags therefore crashes
the kernel. [FIX] Add a NULL check after btrfs_lookup_block_group() in btrfs_may_alloc_data_chunk() and
print and error message for clarity. (CVE-2026-97416)

Solution

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

Plugin Details

Severity: Medium

ID: 475788

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/16/2026

Updated: 10/16/2026

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.6

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Low

Base Score: 1.9

Temporal Score: 1.4

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

CVSS Score Source: CVE-2026-97416

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/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: 9/24/2026

Reference Information

CVE: CVE-2026-97416

Detections

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