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 20098.0.0

high Tenable Cloud Security Plugin ID 471562

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: xfrm: fix sk_dst_cache double-free in
xfrm_user_policy() xfrm_user_policy() clears the socket dst cache with __sk_dst_reset(), i.e. the non-
atomic __sk_dst_set(sk, NULL): it reads sk_dst_cache with rcu_dereference_protected(), stores NULL and
dst_release()s the old dst. That is only safe if no other thread modifies sk_dst_cache concurrently. For a
connected UDP socket that does not hold: the transmit fast path (udp_sendmsg -> sk_dst_check ->
sk_dst_reset) resets the cache locklessly with an atomic xchg(). A per-socket policy change racing a send
can make both sides observe the same old dst and each dst_release() it, dropping the socket's single
reference twice and freeing the xfrm_dst bundle while it is still referenced: BUG: KASAN: slab-use-after-
free in dst_release Write of size 4 at addr ffff88801897b6c0 by task exploit/155 Call Trace: ...
dst_release (... ./include/linux/rcuref.h:109) xfrm_user_policy (./include/net/sock.h:2239
./include/net/sock.h:2256 net/xfrm/xfrm_state.c:3053) do_ip_setsockopt (net/ipv4/ip_sockglue.c:1347)
ip_setsockopt (net/ipv4/ip_sockglue.c:1417) do_sock_setsockopt (net/socket.c:2368) __sys_setsockopt
(net/socket.c:2393) __x64_sys_setsockopt (net/socket.c:2396) do_syscall_64
(arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Reachable
by an unprivileged user via a user+network namespace. Use the atomic sk_dst_reset() so the cache is
cleared and released with a single xchg(): whichever side wins releases the dst once, the other sees NULL
and does nothing. Behaviour is otherwise unchanged. (CVE-2026-64581)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 20098.0.0 or later.

Plugin Details

Severity: High

ID: 471562

Version: Revision 1.6

Type: Local

Family: Google COS Security Checks

Published: 10/3/2026

Updated: 10/6/2026

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: 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-2026-64581

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: 8/5/2026

Reference Information

CVE: CVE-2026-64581

Detections

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