In the Linux kernel, a vulnerability has been resolved concerning the mt76 driver, specifically for the mt7921 device. This vulnerability allows for kernel panics when certain conditions are met, particularly in network configurations involving bridging with Ethernet interfaces. The issue arises from an assumption that adequate headroom will be available for SDIO headers in the skb (socket buffer) structure.
The severity of this issue is currently classified as unknown due to the lack of an official CVSS score. However, the real-world impact is significant, as it can lead to instability in systems utilizing the mt7921AU-based USB 802.11ax interfaces when bridged with Ethernet interfaces. Kernel panics can compromise system reliability, making this a notable concern.
Although the vulnerability is marked as deferred and not actively exploited, organizations should not ignore it. Kernel panics can occur under specific conditions, especially on systems with minimal headroom in received skbs. The implications for stability necessitate awareness and monitoring in network configurations.
Organizations should prioritize monitoring and assessing their deployments to ensure that they do not fall victim to this issue. It is critical that system administrators remain vigilant, especially in configurations that involve bridging interfaces.
Vulnerability Details
This vulnerability allows for kernel panics due to inadequate headroom assumptions in the mt7921 driver. Specifically, the function mt7921_usb_sdio_tx_prepare_skb() makes calls that do not account for the possibility of insufficient headroom in the skb, leading to potential crashes.
The vulnerability is categorized under the Linux kernel and relates to the handling of SDIO headers in the mt76 driver. This defect has been addressed in a subsequent patch, which ensures that adequate headroom is checked before attempting to modify the skb.
The issue was first published on December 9, 2025, and it is important for system administrators to stay updated on kernel patches and related advisories to prevent instability in their systems.
Technical Analysis
The root cause of this issue lies in the way the Linux kernel's mt76 driver handles socket buffers. The function mt7921_usb_sdio_tx_prepare_skb() fails to ensure that there is sufficient headroom in the skb to accommodate the additional SDIO headers that need to be prepended.
This vulnerability is classified as having a low exploitability rating, but it does pose risks under specific network configurations, particularly when bridging different network interfaces. The attack vector is primarily local, as it requires the attacker to have access to the network.
The attack complexity is considered low, as an attacker could leverage this vulnerability without needing extensive privileges or user interaction. The potential impacts on confidentiality, integrity, and availability are notable due to the risk of system crashes.
Risk & Impact Analysis
Real-world deployment of the Linux kernel on systems using the mt7921 driver can expose organizations to considerable risks. The potential for kernel panics in specific network configurations can lead to service interruptions, impacting operational continuity.
Given the nature of this vulnerability, organizations operating in environments where the mt7921 driver is deployed should closely monitor their network configurations and ensure that adequate headroom is accounted for in their socket buffers. Failure to do so could result in unexpected system crashes, degrading user experience and trust.
The urgency for addressing this vulnerability is moderate; organizations should schedule remediation as part of their patch management processes. Remaining vigilant will help mitigate the risks associated with this vulnerability.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
At this time, no specific affected versions of the Linux kernel have been identified. Organizations are advised to monitor their systems for any updates related to the mt76 driver and the mt7921 device.
Mitigation & Remediation
Organizations should ensure they are running the latest stable version of the Linux kernel that includes the fix for this vulnerability. Keeping systems updated is essential for maintaining security and stability.
In the absence of a patch, organizations may implement workarounds by avoiding specific network configurations that involve bridging interfaces utilizing the mt7921 driver.
Additionally, organizations should consider conducting an application security assessment to identify and address potential weaknesses in their configurations.
Detection Guidance
Security teams should monitor logs for any indications of kernel panics related to the mt7921 driver. Behavioral anomalies in network performance, especially during high traffic, should also be investigated.
System changes, particularly those involving network configurations, should be logged and reviewed to ensure compliance with organizational security policies.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability relates to the increasing complexity of network configurations in modern deployments. As organizations leverage diverse networking interfaces, vulnerabilities like CVE-2023-53785 can introduce critical instability.
It serves as a reminder for security teams to adopt a proactive approach to vulnerability management, ensuring regular updates and assessments of network configurations.
For organizations reliant on Linux kernels, conducting regular penetration testing and security assessments can help identify potential vulnerabilities before they are exploited.
Organizations should consider investing in services such as penetration testing to validate their configurations and ensure they are not vulnerable to similar issues.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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