Google: sys-kernel/csql-kernel-6_1, sys-kernel/csql-kernel-6_6, sys-kernel/lakitu-kernel-6_1, sys-kernel/lakitu-kernel-6_6, sys-kernel/lakitu-nc-kernel-6_6, sys-kernel/lakitu-vgpu-kernel-6_6, sys-kernel/tpusev-kernel-6_6: security update to 18613.675.37

high Tenable Cloud Security Plugin ID 466068

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: hwrng: virtio: clamp device-reported
used.len at copy_data() random_recv_done() stores the device-reported used.len directly into
vi->data_avail. copy_data() then indexes vi->data[] using vi->data_idx (advanced by previous copy_data()
calls) and issues a memcpy() without re-validating either value against the posted buffer size
sizeof(vi->data) (SMP_CACHE_BYTES bytes, typically 32 or 64). A malicious or buggy virtio-rng backend can
set used.len beyond sizeof(vi->data), steering the memcpy() past the end of the inline array into adjacent
kmalloc-1k slab bytes. hwrng_fillfn() mixes those bytes into the guest RNG, and guest root can also
observe them directly via /dev/hwrng. Concrete impact is inside the guest: - Memory-safety / hardening:
any virtio-rng backend that over-reports used.len causes the driver to read past vi->data into unrelated
slab contents. hwrng_fillfn() is a kernel thread that runs as soon as the device is probed; no guest
userspace interaction is required to first-trigger the OOB. - Cross-boundary leak (confidential-compute
threat model): a malicious hypervisor cooperating with a malicious or compromised guest root userspace can
use /dev/hwrng as a leak channel for guest-kernel heap data. The host sets a large used.len, guest root
reads /dev/hwrng, and the returned bytes contain guest kernel slab contents that were adjacent to
vi->data. In practice, confidential-compute guests (SEV-SNP, TDX) usually disable virtio-rng entirely, so
this path is narrow, but the fix is still worth carrying because the underlying memory-safety bug
contaminates the guest RNG on any host. KASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend
has been patched to report used.len = 0x10000: BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0
Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52 Call Trace: __asan_memcpy+0x23/0x60
virtio_read+0x394/0x5d0 hwrng_fillfn+0xb2/0x470 kthread+0x2cc/0x3a0 Allocated by task 1:
probe_common+0xa5/0x660 virtio_dev_probe+0x549/0xbc0 The buggy address belongs to the object at
ffff88800ae0b800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes
to the right of allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20) Same class of bug as commit
c04db81cd028 ("net/9p: Fix buffer overflow in USB transport layer"), which hardened usb9pfs_rx_complete()
against unchecked device-reported length in the USB 9p transport. With the clamp at point of use and
array_index_nospec() in place, the same harness boots cleanly: copy_data() returns zero for the bogus
report, the device-supplied bytes after data_idx are discarded, and the driver issues a fresh request.
(CVE-2026-64456)

Solution

Update the sys-kernel/csql-kernel-6_1 library and its related packages to version 18613.675.37 or later.

Plugin Details

Severity: High

ID: 466068

Version: Revision 1.3

Type: Local

Family: Google COS Security Checks

Published: 10/2/2026

Updated: 10/3/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Medium

Score: 6.3

Percentile: 96.68

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-2026-64456

CVSS v3

Risk Factor: High

Base Score: 7.7

Temporal Score: 6.7

Vector: CVSS:3.0/AV:L/AC:L/PR:N/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: 7/23/2026

Reference Information

CVE: CVE-2026-64456

Detections

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