CVE-2026-52983

What it actually does

This is a denial-of-service flaw in the Linux kernel Airoha network driver transmit path. The driver can account transmitted packets against one set of netdev transmit queues while accounting completions across a broader queue set, creating inconsistent Byte Queue Limits accounting. Under affected conditions, the transmit queue state can become imbalanced, potentially causing queue stalls, degraded throughput, transmit timeouts, or loss of network availability on systems using the affected Airoha network interface. The issue is limited to availability impact and does not indicate code execution or privilege escalation from the provided advisory.

Why it matters to the business

Systems that rely on affected Airoha-based network interfaces may experience intermittent or sustained network disruption, which can affect routing, embedded appliances, gateways, or Linux-based devices using this driver. The current public risk appears moderate to low because EPSS is low, the vulnerability is not listed in CISA KEV, ransomware use is not reported, and no public exploit maturity is indicated; however, network-interface denial of service can still create operational outages where these devices are in critical paths.

How an attack unfolds

An attacker would need a way to cause traffic to be transmitted through an affected Airoha network interface. By driving crafted or high-volume transmit activity that exercises queue mappings beyond the transmit queues accounted in the affected path, the driver may misalign packet-in-flight accounting and completion accounting. Over time, this can leave Byte Queue Limits state inconsistent, causing transmit queues to stop, timeout, or behave unpredictably. The result is service degradation or denial of service for network traffic handled by the affected interface. Exploitation is most plausible from a local workload, compromised host process, container with network access, or adjacent traffic pattern that causes the affected device to transmit substantial traffic; the advisory does not support remote unauthenticated code execution.

How to fix it

Update to a Linux kernel version that includes the upstream fix for the Airoha driver BQL accounting imbalance and reset handling in the network device stop path. If vendor kernels are used, apply the relevant distribution, appliance, or hardware-vendor kernel update rather than relying only on upstream version numbers. If immediate patching is not possible, reduce exposure by limiting untrusted workloads that can generate high-volume outbound traffic through affected interfaces, applying traffic shaping or rate limits where feasible, monitoring for transmit queue timeouts, and failing over critical network paths to unaffected interfaces or devices.

How to confirm the fix worked

Confirm whether the running kernel includes the fixed Airoha network driver changes for balanced BQL accounting in the transmit path and reset of all netdev transmit queues in the stop callback. Validate installed kernel package versions against the relevant Linux distribution or device-vendor advisory. On affected hardware, perform controlled transmit-load testing after patching and verify that no transmit queue stalls, NETDEV WATCHDOG events, or Airoha driver transmit timeout messages occur. Confirm that interface counters, queue statistics, and system logs remain stable during sustained outbound traffic.

Typical attack path

1. Identify a Linux system or appliance using the affected Airoha network driver.
2. Generate outbound network traffic through the affected interface, especially traffic patterns that exercise multiple transmit queue mappings.
3. Trigger inconsistent transmit queue accounting between packet submission and completion handling.
4. Cause transmit queue imbalance, stalls, or watchdog timeouts.
5. Disrupt network connectivity or degrade throughput for services relying on that interface.

How to detect it

To determine whether exploitation or triggering has already occurred, review kernel logs, system journals, network monitoring, and interface statistics for signs of transmit queue stalls or driver instability on Airoha interfaces. Useful log sources include dmesg, /var/log/kern.log, /var/log/messages, systemd-journald kernel entries, appliance event logs, and network telemetry showing abrupt throughput drops or interface resets. Look for NETDEV WATCHDOG messages, transmit queue timeout events, repeated interface down/up transitions, unexplained carrier loss, or Airoha/QDMA-related errors correlated with high outbound traffic. Because this issue produces availability symptoms rather than a unique payload or persistent artifact, detection should focus on timing correlation between heavy transmit activity and kernel/network-driver errors.

• airoha
• NETDEV WATCHDOG
• transmit queue timed out
• tx timeout
• queue timed out
• qdma
• airoha_dev_xmit
• airoha_qdma_tx_napi_poll
• Byte Queue Limits
• BQL
• /var/log/kern.log
• /var/log/messages
• dmesg

What your security team should do

• Inventory Linux systems, embedded devices, routers, gateways, and appliances that use Airoha network interfaces or the Linux airoha network driver.
• Prioritize patching systems where affected interfaces carry production, management, routing, or customer-facing traffic.
• Track vendor kernel advisories and apply the kernel update containing the Airoha BQL accounting fix as soon as available for the deployed platform.
• Until patched, monitor for transmit queue timeouts, link degradation, interface resets, and sudden drops in throughput on Airoha-backed interfaces.
• Apply rate limiting or isolate untrusted workloads that can generate sustained outbound traffic through affected devices.
• Plan failover or maintenance windows for critical devices because remediation may require a kernel update and reboot.