In the Linux kernel, a vulnerability has been identified that allows a NULL pointer dereference during unbind operations. This vulnerability is related to the USB gadget driver, specifically concerning the handling of the UVC (USB Video Class) function. The issue arises due to the timing-based synchronization approach that has proven insufficient during power management transitions.
The vulnerability allows attackers to trigger kernel panics by exploiting the race condition that occurs when the power management subsystem attempts to freeze user space processes. This incident can occur when the subroutine responsible for unbinding the USB gadget fails to properly synchronize with the power management state, resulting in a NULL pointer dereference.
Risk to organizations includes potential system instability and crashes, impacting the availability of systems reliant on USB devices. Organizations should consider the implications of this vulnerability, especially in environments where USB devices are critical.
Currently, the vulnerability is classified as awaiting analysis, and there is no public exploit confirmed. However, organizations are advised to monitor this situation closely.
Vulnerability Details
The official description indicates that the vulnerability allows for a NULL pointer dereference during unbind operations in the USB gadget subsystem of the Linux kernel. This issue is triggered by a race condition during power management transitions, leading to kernel panics when processes attempt to access nullified pointers.
The vulnerability has been documented in commit b81ac4395bbe, which attempted to introduce synchronization mechanisms that ultimately proved inadequate under specific conditions.
At this stage, the severity level is classified as unknown, and the CVSS score is not available. Organizations should treat this vulnerability with caution and follow any developments regarding patches or mitigations.
Technical Analysis
The root cause of this vulnerability lies in the synchronization mechanism within the USB gadget driver. The kernel uses a timing-based approach to handle unbinding, which is insufficient during power management transitions. When the PM subsystem freezes user space processes, the synchronization waits can be aborted prematurely, leading to a state where the gadget pointer is nullified.
The attack vector is local, as it requires the ability to interact with the USB subsystem. The complexity of the attack is low, and no user interaction is required to trigger the vulnerability. The impacts on confidentiality, integrity, and availability are significant, as the vulnerability can lead to system crashes.
Risk & Impact Analysis
The real-world risk associated with this vulnerability involves the potential for system instability and crashes, particularly in environments where USB devices are critical. Organizations should assess the impact this vulnerability could have on their operations.
Urgency assessment indicates that, while the vulnerability is currently awaiting analysis, organizations should not ignore the risks associated with kernel panics that could disrupt services.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
Specific version information is currently not available. Organizations should assume that all versions of the Linux kernel prior to the resolution of this issue could be affected.
Mitigation & Remediation
Organizations should monitor for updates regarding this vulnerability and apply patches as soon as they are released. In the meantime, users are advised to consider implementing additional monitoring and logging around USB interactions to detect any unusual behavior.
Detection Guidance
Monitoring kernel logs for unexpected panics related to USB gadget operations can provide early warning of this vulnerability being exploited. Additionally, tracking changes in USB device states and examining user space process freezes can help identify potential issues related to this vulnerability.
AppSecure Threat Intelligence Insight
Long-term significance of this vulnerability relates to the ongoing challenges faced in the management of power states in the Linux kernel, particularly concerning USB devices. This incident underscores the importance of robust synchronization mechanisms in preventing critical failures within the system.
Security teams should take this vulnerability as a reminder of the complexities in kernel development and the potential for seemingly minor code changes to introduce significant risks. A focus on thorough testing and review processes can help mitigate similar vulnerabilities in the future.
Organizations are encouraged to review their incident response plans and ensure they can rapidly address kernel-related vulnerabilities as part of their broader security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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