Upstream information
Description
In the Linux kernel, the following vulnerability has been resolved:Revert "wireguard: device: enable threaded NAPI"
This reverts commit 933466fc50a8e4eb167acbd0d8ec96a078462e9c which is
commit db9ae3b6b43c79b1ba87eea849fd65efa05b4b2e upstream.
We have had three independent production user reports in combination
with Cilium utilizing WireGuard as encryption underneath that k8s Pod
E/W traffic to certain peer nodes fully stalled. The situation appears
as follows:
- Occurs very rarely but at random times under heavy networking load.
- Once the issue triggers the decryption side stops working completely
for that WireGuard peer, other peers keep working fine. The stall
happens also for newly initiated connections towards that particular
WireGuard peer.
- Only the decryption side is affected, never the encryption side.
- Once it triggers, it never recovers and remains in this state,
the CPU/mem on that node looks normal, no leak, busy loop or crash.
- bpftrace on the affected system shows that wg_prev_queue_enqueue
fails, thus the MAX_QUEUED_PACKETS (1024 skbs!) for the peer's
rx_queue is reached.
- Also, bpftrace shows that wg_packet_rx_poll for that peer is never
called again after reaching this state for that peer. For other
peers wg_packet_rx_poll does get called normally.
- Commit db9ae3b ("wireguard: device: enable threaded NAPI")
switched WireGuard to threaded NAPI by default. The default has
not been changed for triggering the issue, neither did CPU
hotplugging occur (i.e. 5bd8de2 ("wireguard: queueing: always
return valid online CPU in wg_cpumask_choose_online()")).
- The issue has been observed with stable kernels of v5.15 as well as
v6.1. It was reported to us that v5.10 stable is working fine, and
no report on v6.6 stable either (somewhat related discussion in [0]
though).
- In the WireGuard driver the only material difference between v5.10
stable and v5.15 stable is the switch to threaded NAPI by default.
[0] https://lore.kernel.org/netdev/CA+wXwBTT74RErDGAnj98PqS=wvdh8eM1pi4q6tTdExtjnokKqA@mail.gmail.com/
Breakdown of the problem:
1) skbs arriving for decryption are enqueued to the peer->rx_queue in
wg_packet_consume_data via wg_queue_enqueue_per_device_and_peer.
2) The latter only moves the skb into the MPSC peer queue if it does
not surpass MAX_QUEUED_PACKETS (1024) which is kept track in an
atomic counter via wg_prev_queue_enqueue.
3) In case enqueueing was successful, the skb is also queued up
in the device queue, round-robin picks a next online CPU, and
schedules the decryption worker.
4) The wg_packet_decrypt_worker, once scheduled, picks these up
from the queue, decrypts the packets and once done calls into
wg_queue_enqueue_per_peer_rx.
5) The latter updates the state to PACKET_STATE_CRYPTED on success
and calls napi_schedule on the per peer->napi instance.
6) NAPI then polls via wg_packet_rx_poll. wg_prev_queue_peek checks
on the peer->rx_queue. It will wg_prev_queue_dequeue if the
queue->peeked skb was not cached yet, or just return the latter
otherwise. (wg_prev_queue_drop_peeked later clears the cache.)
7) From an ordering perspective, the peer->rx_queue has skbs in order
while the device queue with the per-CPU worker threads from a
global ordering PoV can finish the decryption and signal the skb
PACKET_STATE_CRYPTED out of order.
8) A situation can be observed that the first packet coming in will
be stuck waiting for the decryption worker to be scheduled for
a longer time when the system is under pressure.
9) While this is the case, the other CPUs in the meantime finish
decryption and call into napi_schedule.
10) Now in wg_packet_rx_poll it picks up the first in-order skb
from the peer->rx_queue and sees that its state is still
PACKET_STATE_UNCRYPTED. The NAPI poll routine then exits e
---truncated---
SUSE information
Overall state of this security issue: Resolved
This issue is currently rated as having moderate severity.
| CVSS detail | SUSE |
|---|---|
| Base Score | 5.9 |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | High |
| CVSSv3 Version | 3.1 |
Note from the SUSE Security Team on the kernel-default package
SUSE will no longer fix all CVEs in the Linux Kernel anymore, but declare some bug classes as won't fix. Please refer to TID 21496 for more details. SUSE Bugzilla entry: 1269110 [NEW] 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 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Desktop 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Live Patching 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Live Patching 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Micro 5.3 | kernel-default | Already fixed |
| SUSE Linux Enterprise Micro 5.3 | kernel-rt | Already fixed |
| SUSE Linux Enterprise Micro 5.3 | kernel-source | Already fixed |
| SUSE Linux Enterprise Micro 5.3 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Micro 5.4 | kernel-default | Already fixed |
| SUSE Linux Enterprise Micro 5.4 | kernel-rt | Already fixed |
| SUSE Linux Enterprise Micro 5.4 | kernel-source | Already fixed |
| SUSE Linux Enterprise Micro 5.4 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Micro 5.5 | kernel-default | Already fixed |
| SUSE Linux Enterprise Micro 5.5 | kernel-source | Already fixed |
| SUSE Linux Enterprise Micro 5.5 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Public Cloud 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Module for Public Cloud 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Real Time 15 SP7 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Server 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 16.0 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 16.0 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 16.1 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP applications 16.0 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server for SAP applications 16.0 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP applications 16.1 | kernel-source | Already fixed |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Micro 6.0 | kernel-default | Already fixed |
| SUSE Linux Micro 6.0 | kernel-source | Already fixed |
| SUSE Linux Micro 6.0 | kernel-source-rt | Already fixed |
| SUSE Linux Micro 6.1 | kernel-default | Already fixed |
| SUSE Linux Micro 6.1 | kernel-source | Already fixed |
| SUSE Linux Micro 6.1 | kernel-source-rt | Already fixed |
| SUSE Linux Micro 6.2 | kernel-default | Already fixed |
| SUSE Linux Micro 6.2 | kernel-source | Already fixed |
| SUSE Real Time Module 15 SP7 | kernel-source-rt | Already fixed |
| openSUSE Leap 16.0 | kernel-source | Already fixed |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 15 SP4 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-default | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-default | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-source | Already fixed |
| SUSE Linux Enterprise Live Patching 12 SP5 | kernel-default | Not affected |
| SUSE Linux Enterprise Live Patching 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Live Patching 15 SP4 | kernel-default | Already fixed |
| SUSE Linux Enterprise Live Patching 15 SP4 | kernel-source | Already fixed |
| SUSE Linux Enterprise Live Patching 15 SP5 | kernel-default | Already fixed |
| SUSE Linux Enterprise Live Patching 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-default | Not affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | kernel-default | Not affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP4 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 15 SP6 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 15 SP6-LTSS | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 15 SP6-LTSS | kernel-source | Already fixed |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-source | Already fixed |
| SUSE Manager Proxy 4.3 | kernel-source | Already fixed |
| SUSE Manager Proxy LTS 4.3 | kernel-source | Already fixed |
| SUSE Manager Retail Branch Server 4.3 | kernel-source | Already fixed |
| SUSE Manager Retail Branch Server LTS 4.3 | kernel-source | Already fixed |
| SUSE Manager Server 4.3 | kernel-source | Already fixed |
| SUSE Manager Server LTS 4.3 | kernel-source | Already fixed |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE CaaS Platform 4.0 | kernel-source | Not affected |
| SUSE Enterprise Storage 6 | kernel-source | Not affected |
| SUSE Enterprise Storage 7 | kernel-source | Not affected |
| SUSE Enterprise Storage 7.1 | kernel-source | Already fixed |
| SUSE Linux Enterprise Desktop 11 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 12 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP3 | kernel-source | Already fixed |
| SUSE Linux Enterprise Desktop 15 SP4 | kernel-source | Already fixed |
| SUSE Linux Enterprise Desktop 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise Desktop 15 SP6 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | kernel-source | Already fixed |
| SUSE Linux Enterprise Micro 5.0 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.1 | kernel-default | Already fixed |
| SUSE Linux Enterprise Micro 5.2 | kernel-default | Already fixed |
| SUSE Linux Enterprise Micro 5.2 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | kernel-source | Already fixed |
| SUSE Linux Enterprise Real Time 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP3 | kernel-source | Already fixed |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source | Already fixed |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Real Time 15 SP5 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Server 11 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 11 SP4-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP4-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP4-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 12 SP4-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP3 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 15 SP3-BCL | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-source | Already fixed |
| SUSE Manager Proxy 4.0 | kernel-source | Not affected |
| SUSE Manager Proxy 4.1 | kernel-source | Not affected |
| SUSE Manager Proxy 4.2 | kernel-source | Already fixed |
| SUSE Manager Retail Branch Server 4.0 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.1 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.2 | kernel-source | Already fixed |
| SUSE Manager Server 4.0 | kernel-source | Not affected |
| SUSE Manager Server 4.1 | kernel-source | Not affected |
| SUSE Manager Server 4.2 | kernel-source | Already fixed |
| SUSE OpenStack Cloud 9 | kernel-source | Not affected |
| SUSE OpenStack Cloud Crowbar 9 | kernel-source | Not affected |
| SUSE Real Time Module 15 SP4 | kernel-source-rt | Already fixed |
| SUSE Real Time Module 15 SP5 | kernel-source-rt | Already fixed |
| openSUSE Leap 15.3 | kernel-source | Already fixed |
| openSUSE Leap 15.4 | kernel-source | Already fixed |
| openSUSE Leap 15.4 | kernel-source-rt | Already fixed |
| openSUSE Leap 15.5 | kernel-source | Already fixed |
| openSUSE Leap 15.5 | kernel-source-rt | Already fixed |
| openSUSE Leap 15.6 | kernel-source | Already fixed |
SUSE Timeline for this CVE
CVE page created: Wed Jun 24 20:01:26 2026CVE page last modified: Thu Jun 25 13:29:52 2026