Upstream information

CVE-2024-56770 at MITRE

Description

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

net/sched: netem: account for backlog updates from child qdisc

In general, 'qlen' of any classful qdisc should keep track of the
number of packets that the qdisc itself and all of its children holds.
In case of netem, 'qlen' only accounts for the packets in its internal
tfifo. When netem is used with a child qdisc, the child qdisc can use
'qdisc_tree_reduce_backlog' to inform its parent, netem, about created
or dropped SKBs. This function updates 'qlen' and the backlog statistics
of netem, but netem does not account for changes made by a child qdisc.
'qlen' then indicates the wrong number of packets in the tfifo.
If a child qdisc creates new SKBs during enqueue and informs its parent
about this, netem's 'qlen' value is increased. When netem dequeues the
newly created SKBs from the child, the 'qlen' in netem is not updated.
If 'qlen' reaches the configured sch->limit, the enqueue function stops
working, even though the tfifo is not full.

Reproduce the bug:
Ensure that the sender machine has GSO enabled. Configure netem as root
qdisc and tbf as its child on the outgoing interface of the machine
as follows:
$ tc qdisc add dev <oif> root handle 1: netem delay 100ms limit 100
$ tc qdisc add dev <oif> parent 1:0 tbf rate 50Mbit burst 1542 latency 50ms

Send bulk TCP traffic out via this interface, e.g., by running an iPerf3
client on the machine. Check the qdisc statistics:
$ tc -s qdisc show dev <oif>

Statistics after 10s of iPerf3 TCP test before the fix (note that
netem's backlog > limit, netem stopped accepting packets):
qdisc netem 1: root refcnt 2 limit 1000 delay 100ms
Sent 2767766 bytes 1848 pkt (dropped 652, overlimits 0 requeues 0)
backlog 4294528236b 1155p requeues 0
qdisc tbf 10: parent 1:1 rate 50Mbit burst 1537b lat 50ms
Sent 2767766 bytes 1848 pkt (dropped 327, overlimits 7601 requeues 0)
backlog 0b 0p requeues 0

Statistics after the fix:
qdisc netem 1: root refcnt 2 limit 1000 delay 100ms
Sent 37766372 bytes 24974 pkt (dropped 9, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
qdisc tbf 10: parent 1:1 rate 50Mbit burst 1537b lat 50ms
Sent 37766372 bytes 24974 pkt (dropped 327, overlimits 96017 requeues 0)
backlog 0b 0p requeues 0

tbf segments the GSO SKBs (tbf_segment) and updates the netem's 'qlen'.
The interface fully stops transferring packets and "locks". In this case,
the child qdisc and tfifo are empty, but 'qlen' indicates the tfifo is at
its limit and no more packets are accepted.

This patch adds a counter for the entries in the tfifo. Netem's 'qlen' is
only decreased when a packet is returned by its dequeue function, and not
during enqueuing into the child qdisc. External updates to 'qlen' are thus
accounted for and only the behavior of the backlog statistics changes. As
in other qdiscs, 'qlen' then keeps track of how many packets are held in
netem and all of its children. As before, sch->limit remains as the
maximum number of packets in the tfifo. The same applies to netem's
backlog statistics.

SUSE information

Overall state of this security issue: New

This issue is currently rated as having moderate severity.

No SUSE Bugzilla entries cross referenced.

No SUSE Security Announcements cross referenced.


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise Desktop 15 SP6 kernel-default Analysis
SUSE Linux Enterprise Desktop 15 SP6 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-default Analysis
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-source-azure Analysis
SUSE Linux Enterprise Live Patching 15 SP6 kernel-default Analysis
SUSE Linux Enterprise Live Patching 15 SP6 kernel-source Analysis
SUSE Linux Enterprise Micro 5.1 kernel-default Analysis
SUSE Linux Enterprise Micro 5.1 kernel-rt Analysis
SUSE Linux Enterprise Micro 5.1 kernel-source Analysis
SUSE Linux Enterprise Micro 5.1 kernel-source-rt Analysis
SUSE Linux Enterprise Micro 5.2 kernel-default Analysis
SUSE Linux Enterprise Micro 5.2 kernel-rt Analysis
SUSE Linux Enterprise Micro 5.2 kernel-source Analysis
SUSE Linux Enterprise Micro 5.2 kernel-source-rt Analysis
SUSE Linux Enterprise Micro 5.3 kernel-default Analysis
SUSE Linux Enterprise Micro 5.3 kernel-rt Analysis
SUSE Linux Enterprise Micro 5.3 kernel-source Analysis
SUSE Linux Enterprise Micro 5.3 kernel-source-rt Analysis
SUSE Linux Enterprise Micro 5.4 kernel-default Analysis
SUSE Linux Enterprise Micro 5.4 kernel-rt Analysis
SUSE Linux Enterprise Micro 5.4 kernel-source Analysis
SUSE Linux Enterprise Micro 5.4 kernel-source-rt Analysis
SUSE Linux Enterprise Micro 5.5 kernel-default Analysis
SUSE Linux Enterprise Micro 5.5 kernel-source Analysis
SUSE Linux Enterprise Micro 5.5 kernel-source-rt Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP6 kernel-default Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP6 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP6 kernel-default Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP6 kernel-source Analysis
SUSE Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure Analysis
SUSE Linux Enterprise Real Time 15 SP6 kernel-source-rt Analysis
SUSE Linux Enterprise Server 15 SP6 kernel-default Analysis
SUSE Linux Enterprise Server 15 SP6 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP6 kernel-source-azure Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-default Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source-azure Analysis
SUSE Linux Micro 6.0 kernel-default Analysis
SUSE Linux Micro 6.0 kernel-source Analysis
SUSE Linux Micro 6.0 kernel-source-rt Analysis
SUSE Linux Micro 6.1 kernel-default Analysis
SUSE Linux Micro 6.1 kernel-source Analysis
SUSE Linux Micro 6.1 kernel-source-rt Analysis
SUSE Manager Proxy 4.3 kernel-default Analysis
SUSE Manager Proxy 4.3 kernel-source Analysis
SUSE Manager Retail Branch Server 4.3 kernel-default Analysis
SUSE Manager Retail Branch Server 4.3 kernel-source Analysis
SUSE Manager Server 4.3 kernel-default Analysis
SUSE Manager Server 4.3 kernel-source Analysis
SUSE Real Time Module 15 SP6 kernel-source-rt Analysis
openSUSE Leap 15.6 kernel-default Analysis
openSUSE Leap 15.6 kernel-source Analysis
openSUSE Leap 15.6 kernel-source-azure Analysis
openSUSE Leap 15.6 kernel-source-rt Analysis
Products under Long Term Service Pack support and receiving important and critical security fixes.
SUSE Linux Enterprise High Availability Extension 12 SP5 kernel-default Analysis
SUSE Linux Enterprise High Availability Extension 12 SP5 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP3 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-default Analysis
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP4 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default Analysis
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-default Unsupported
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source Unsupported
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source-azure Analysis
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS kernel-default Analysis
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-default Analysis
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-source Analysis
SUSE Linux Enterprise Live Patching 12 SP5 kernel-default Analysis
SUSE Linux Enterprise Live Patching 12 SP5 kernel-source Analysis
SUSE Linux Enterprise Live Patching 15 SP3 kernel-default Analysis
SUSE Linux Enterprise Live Patching 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Live Patching 15 SP4 kernel-default Analysis
SUSE Linux Enterprise Live Patching 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Live Patching 15 SP5 kernel-default Analysis
SUSE Linux Enterprise Live Patching 15 SP5 kernel-source Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-default Unsupported
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-source Unsupported
SUSE Linux Enterprise Module for Development Tools 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-default Unsupported
SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-source Unsupported
SUSE Linux Enterprise Module for Legacy 15 SP5 kernel-default Unsupported
SUSE Linux Enterprise Module for Legacy 15 SP5 kernel-source Unsupported
SUSE Linux Enterprise Module for Public Cloud 15 SP5 kernel-source-azure Analysis
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default Analysis
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-source Analysis
SUSE Linux Enterprise Server 12 SP5 kernel-source Analysis
SUSE Linux Enterprise Server 12 SP5 kernel-source-azure Analysis
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-source-azure Analysis
SUSE Linux Enterprise Server 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 15 SP5 kernel-default Unsupported
SUSE Linux Enterprise Server 15 SP5 kernel-source Unsupported
SUSE Linux Enterprise Server 15 SP5 kernel-source-azure Analysis
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-source Analysis
SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-source Analysis
SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-source-azure Analysis
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-default Analysis
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-default Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-default Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-default Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source-azure Analysis
Products past their end of life and not receiving proactive updates anymore.
HPE Helion OpenStack 8 kernel-source Analysis
SUSE CaaS Platform 4.0 kernel-source Analysis
SUSE CaaS Platform Toolchain 3 kernel-source Analysis
SUSE Enterprise Storage 6 kernel-source Analysis
SUSE Enterprise Storage 7 kernel-source Analysis
SUSE Enterprise Storage 7.1 kernel-source Analysis
SUSE Linux Enterprise Desktop 11 SP4 kernel-source Analysis
SUSE Linux Enterprise Desktop 12 SP2 kernel-source Analysis
SUSE Linux Enterprise Desktop 12 SP3 kernel-source Analysis
SUSE Linux Enterprise Desktop 12 SP4 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP1 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Desktop 15 SP5 kernel-default Unsupported
SUSE Linux Enterprise Desktop 15 SP5 kernel-source Unsupported
SUSE Linux Enterprise High Performance Computing 15 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP1 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP2 kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15-ESPOS kernel-source Analysis
SUSE Linux Enterprise High Performance Computing 15-LTSS kernel-source Analysis
SUSE Linux Enterprise Micro 5.0 kernel-default Analysis
SUSE Linux Enterprise Module for Basesystem 15 kernel-source Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP1 kernel-source Analysis
SUSE Linux Enterprise Module for Basesystem 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP1 kernel-source Analysis
SUSE Linux Enterprise Module for Development Tools 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Point of Sale 12 SP2-CLIENT kernel-source Analysis
SUSE Linux Enterprise Real Time 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Real Time 15 SP3 kernel-source Analysis
SUSE Linux Enterprise Real Time 15 SP3 kernel-source-rt Analysis
SUSE Linux Enterprise Real Time 15 SP4 kernel-source Analysis
SUSE Linux Enterprise Real Time 15 SP4 kernel-source-rt Analysis
SUSE Linux Enterprise Real Time 15 SP5 kernel-source-rt Analysis
SUSE Linux Enterprise Server 11 SP4 kernel-source Analysis
SUSE Linux Enterprise Server 11 SP4 LTSS kernel-default Analysis
SUSE Linux Enterprise Server 11 SP4 LTSS kernel-source Analysis
SUSE Linux Enterprise Server 11 SP4-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 12 SP2 kernel-source Analysis
SUSE Linux Enterprise Server 12 SP2-BCL kernel-source Analysis
SUSE Linux Enterprise Server 12 SP2-ESPOS kernel-source Analysis
SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 12 SP2-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 12 SP3 kernel-source Analysis
SUSE Linux Enterprise Server 12 SP3-BCL kernel-source Analysis
SUSE Linux Enterprise Server 12 SP3-ESPOS kernel-source Analysis
SUSE Linux Enterprise Server 12 SP3-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 12 SP4 kernel-source Analysis
SUSE Linux Enterprise Server 12 SP4-ESPOS kernel-source Analysis
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 15 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP1 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP1-BCL kernel-source Analysis
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 15 SP2 kernel-source Analysis
SUSE Linux Enterprise Server 15 SP2-BCL kernel-source Analysis
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-source Analysis
SUSE Linux Enterprise Server 15 SP3-BCL kernel-source Analysis
SUSE Linux Enterprise Server 15-LTSS kernel-default Analysis
SUSE Linux Enterprise Server 15-LTSS kernel-source Analysis
SUSE Linux Enterprise Server for Raspberry Pi 12 SP2 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 12 SP3 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-source Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-source Analysis
SUSE Manager Proxy 4.0 kernel-source Analysis
SUSE Manager Proxy 4.1 kernel-source Analysis
SUSE Manager Proxy 4.2 kernel-source Analysis
SUSE Manager Retail Branch Server 4.0 kernel-source Analysis
SUSE Manager Retail Branch Server 4.1 kernel-source Analysis
SUSE Manager Retail Branch Server 4.2 kernel-source Analysis
SUSE Manager Server 4.0 kernel-source Analysis
SUSE Manager Server 4.1 kernel-source Analysis
SUSE Manager Server 4.2 kernel-source Analysis
SUSE OpenStack Cloud 7 kernel-source Analysis
SUSE OpenStack Cloud 8 kernel-source Analysis
SUSE OpenStack Cloud 9 kernel-source Analysis
SUSE OpenStack Cloud Crowbar 8 kernel-source Analysis
SUSE OpenStack Cloud Crowbar 9 kernel-source Analysis
SUSE Real Time Module 15 SP3 kernel-source-rt Analysis
SUSE Real Time Module 15 SP4 kernel-source-rt Analysis
SUSE Real Time Module 15 SP5 kernel-source-rt Analysis
openSUSE Leap 15.3 kernel-source Analysis
openSUSE Leap 15.3 kernel-source-rt Analysis
openSUSE Leap 15.4 kernel-source Analysis
openSUSE Leap 15.4 kernel-source-azure Analysis
openSUSE Leap 15.4 kernel-source-rt Analysis
openSUSE Leap 15.5 kernel-source Analysis
openSUSE Leap 15.5 kernel-source-azure Analysis
openSUSE Leap 15.5 kernel-source-rt Analysis


SUSE Timeline for this CVE

CVE page created: Wed Jan 8 20:00:43 2025
CVE page last modified: Thu Jan 9 20:04:28 2025