In the Linux kernel, the following vulnerability has been resolved:

net: openvswitch: fix overwriting ct original tuple for ICMPv6

OVS_PACKET_CMD_EXECUTE has 3 main attributes:
- OVS_PACKET_ATTR_KEY - Packet metadata in a netlink format.
- OVS_PACKET_ATTR_PACKET - Binary packet content.
- OVS_PACKET_ATTR_ACTIONS - Actions to execute on the packet.

OVS_PACKET_ATTR_KEY is parsed first to populate sw_flow_key structure
with the metadata like conntrack state, input port, recirculation id,
etc. Then the packet itself gets parsed to populate the rest of the
keys from the packet headers.

Whenever the packet parsing code starts parsing the ICMPv6 header, it
first zeroes out fields in the key corresponding to Neighbor Discovery
information even if it is not an ND packet.

It is an 'ipv6.nd' field. However, the 'ipv6' is a union that shares
the space between 'nd' and 'ct_orig' that holds the original tuple
conntrack metadata parsed from the OVS_PACKET_ATTR_KEY.

ND packets should not normally have conntrack state, so it's fine to
share the space, but normal ICMPv6 Echo packets or maybe other types of
ICMPv6 can have the state attached and it should not be overwritten.

The issue results in all but the last 4 bytes of the destination
address being wiped from the original conntrack tuple leading to
incorrect packet matching and potentially executing wrong actions
in case this packet recirculates within the datapath or goes back
to userspace.

ND fields should not be accessed in non-ND packets, so not clearing
them should be fine. Executing memset() only for actual ND packets to
avoid the issue.

Initializing the whole thing before parsing is needed because ND packet
may not contain all the options.

The issue only affects the OVS_PACKET_CMD_EXECUTE path and doesn't
affect packets entering OVS datapath from network interfaces, because
in this case CT metadata is populated from skb after the packet is
already parsed.
History

Wed, 16 Oct 2024 02:30:00 +0000

Type Values Removed Values Added
CPEs cpe:/o:redhat:rhel_eus:8.8

Wed, 02 Oct 2024 14:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat rhel Eus
CPEs cpe:/a:redhat:rhel_eus:9.2
cpe:/a:redhat:rhel_eus:9.2::nfv
Vendors & Products Redhat rhel Eus

Tue, 24 Sep 2024 11:00:00 +0000

Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:8

Tue, 24 Sep 2024 06:30:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:enterprise_linux:8::nfv

Fri, 16 Aug 2024 18:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T09:14:04.228Z

Reserved: 2024-06-18T19:36:34.921Z

Link: CVE-2024-38558

cve-icon Vulnrichment

Updated: 2024-08-02T04:12:25.358Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-06-19T14:15:15.983

Modified: 2024-11-21T09:26:20.560

Link: CVE-2024-38558

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-06-19T00:00:00Z

Links: CVE-2024-38558 - Bugzilla

cve-icon OpenCVE Enrichment

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