Google: sys-kernel/csql-kernel-6_6, 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 18613.731.2

critical Tenable Cloud Security Plugin ID 465846

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: SUNRPC: pin upper rpc_clnt across the
TLS connect_worker The TLS connect path has a use-after-free: nothing pins the upper rpc_clnt across the
delayed connect_worker. xs_connect() stores task->tk_client in sock_xprt::clnt as a raw pointer and queues
the worker; for TLS-secured transports that worker is xs_tcp_tls_setup_socket(), which reads several
fields out of the saved pointer (cl_timeout, cl_program, cl_prog, cl_vers, cl_cred, cl_stats) to construct
the args for the inner handshake rpc_clnt. The xprt does not reference the rpc_clnt; the rpc_clnt
references the xprt. xs_destroy() does cancel the connect_worker, but it runs only when the xprt's
refcount drops to zero, which cannot happen until the rpc_clnt releases its cl_xprt reference in
rpc_free_client_work(). When a TLS handshake fails fatally (for example, an mTLS mount whose client cert
does not match the server), the connecting task is woken with -EACCES and exits, the mount caller invokes
rpc_shutdown_client(), and the upper rpc_clnt is freed before the queued connect_worker fires.
xs_tcp_tls_setup_socket() then dereferences the freed clnt, producing the refcount_t underflow Michael
Nemanov reported. Take a reference on the upper rpc_clnt in xs_connect() for TLS transports via a new
rpc_hold_client() helper, and drop it in the connect_worker's exit path with rpc_release_client(). The
xprt_lock_connect() / xprt_unlock_connect() pairing already serialises xs_connect() with
xs_tcp_tls_setup_socket(), so the take and release are balanced one-for-one. The non-TLS connect worker
(xs_tcp_setup_socket) never reads sock_xprt::clnt, so leave that path alone and avoid the clnt-holds-xprt-
holds-clnt cycle that would otherwise prevent xprt destruction. (CVE-2026-72317)

Solution

Update the sys-kernel/csql-kernel-6_6 library and its related packages to version 18613.731.2 or later.

Plugin Details

Severity: Critical

ID: 465846

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: 4.9

Percentile: 58.27

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-72317

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/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: 8/11/2026

Reference Information

CVE: CVE-2026-72317

Detections

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