Google: sys-kernel/csql-kernel-6_1, sys-kernel/lakitu-kernel-6_1: security update to 18244.85.5

medium Tenable Cloud Security Plugin ID 450660

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: netfilter: bridge: confirm multicast
packets before passing them up the stack conntrack nf_confirm logic cannot handle cloned skbs referencing
the same nf_conn entry, which will happen for multicast (broadcast) frames on bridges. Example: macvlan0 |
br0 / \ ethX ethY ethX (or Y) receives a L2 multicast or broadcast packet containing an IP packet, flow is
not yet in conntrack table. 1. skb passes through bridge and fake-ip (br_netfilter)Prerouting. ->
skb->_nfct now references a unconfirmed entry 2. skb is broad/mcast packet. bridge now passes clones out
on each bridge interface. 3. skb gets passed up the stack. 4. In macvlan case, macvlan driver retains
clone(s) of the mcast skb and schedules a work queue to send them out on the lower devices. The clone
skb->_nfct is not a copy, it is the same entry as the original skb. The macvlan rx handler then returns
RX_HANDLER_PASS. 5. Normal conntrack hooks (in NF_INET_LOCAL_IN) confirm the orig skb. The Macvlan
broadcast worker and normal confirm path will race. This race will not happen if step 2 already confirmed
a clone. In that case later steps perform skb_clone() with skb->_nfct already confirmed (in hash table).
This works fine. But such confirmation won't happen when eb/ip/nftables rules dropped the packets before
they reached the nf_confirm step in postrouting. Pablo points out that nf_conntrack_bridge doesn't allow
use of stateful nat, so we can safely discard the nf_conn entry and let inet call conntrack again. This
doesn't work for bridge netfilter: skb could have a nat transformation. Also bridge nf prevents re-
invocation of inet prerouting via 'sabotage_in' hook. Work around this problem by explicit confirmation of
the entry at LOCAL_IN time, before upper layer has a chance to clone the unconfirmed entry. The downside
is that this disables NAT and conntrack helpers. Alternative fix would be to add locking to all code parts
that deal with unconfirmed packets, but even if that could be done in a sane way this opens up other
problems, for example: -m physdev --physdev-out eth0 -j SNAT --snat-to 1.2.3.4 -m physdev --physdev-out
eth1 -j SNAT --snat-to 1.2.3.5 For multicast case, only one of such conflicting mappings will be created,
conntrack only handles 1:1 NAT mappings. Users should set create a setup that explicitly marks such
traffic NOTRACK (conntrack bypass) to avoid this, but we cannot auto-bypass them, ruleset might have
accept rules for untracked traffic already, so user-visible behaviour would change. (CVE-2024-27415)

Solution

Update the sys-kernel/csql-kernel-6_1 library and its related packages to version 18244.85.5 or later.

Plugin Details

Severity: Medium

ID: 450660

Version: Revision 1.2

Type: Local

Family: Google COS Security Checks

Published: 10/1/2026

Updated: 10/2/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.18

Vendor

Vendor Severity: MEDIUM

CVSS v2

Risk Factor: Low

Base Score: 3.8

Temporal Score: 2.8

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

CVSS Score Source: CVE-2024-27415

CVSS v3

Risk Factor: Medium

Base Score: 4.7

Temporal Score: 4.1

Vector: CVSS:3.0/AV:L/AC:H/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

Reference Information

CVE: CVE-2024-27415

Detections

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