CVE-2024-53240 in Xen
Summary
by MITRE • 12/24/2024
In the Linux kernel, the following vulnerability has been resolved:
xen/netfront: fix crash when removing device
When removing a netfront device directly after a suspend/resume cycle it might happen that the queues have not been setup again, causing a crash during the attempt to stop the queues another time.
Fix that by checking the queues are existing before trying to stop them.
This is XSA-465 / CVE-2024-53240.
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Analysis
by VulDB Data Team • 10/08/2025
The vulnerability described in CVE-2024-53240 represents a critical race condition within the Linux kernel's Xen netfront driver implementation that can lead to system crashes during device removal operations. This issue specifically manifests when a netfront device is removed immediately following a suspend/resume cycle, creating a scenario where the network queue structures remain in an inconsistent state. The vulnerability stems from improper state management within the virtualized network driver subsystem, where the driver fails to properly validate queue existence before attempting cleanup operations. Such conditions can occur in virtualized environments where hypervisor-level operations like suspend/resume are frequently performed, particularly in cloud computing and containerized deployments where resource management is dynamic.
The technical flaw resides in the absence of proper queue validation checks within the device removal pathway of the xen/netfront driver. During normal operation, the netfront driver manages network communication between guest operating systems and the Xen hypervisor through queued network packets. When a suspend/resume cycle occurs, the driver's internal state management becomes disrupted, leaving queue structures in an undefined state. The vulnerability specifically occurs because the driver attempts to stop queues without first verifying their existence, leading to null pointer dereferences or invalid memory access patterns that ultimately result in kernel crashes. This type of flaw falls under CWE-476 which describes NULL Pointer Dereference, and represents a classic case of improper state validation in concurrent systems.
The operational impact of this vulnerability extends beyond simple system crashes to potentially disrupt network connectivity in virtualized environments and compromise system stability during maintenance operations. In production cloud environments where instances frequently undergo suspend/resume cycles for resource optimization, this vulnerability could lead to cascading failures affecting multiple virtual machines simultaneously. The crash occurs during device removal operations which are routine maintenance tasks, making this vulnerability particularly dangerous as it can be triggered by legitimate system operations rather than malicious attacks. Attackers could potentially exploit this to cause denial of service conditions, especially in environments where automated scaling or maintenance operations are common, as demonstrated by ATT&CK technique T1499.201 which covers the use of system shutdown or reboot to disrupt services.
Mitigation strategies for this vulnerability should focus on implementing proper state validation mechanisms within the driver's cleanup pathways. The fix introduced addresses the core issue by adding queue existence checks before attempting to stop them, preventing the invalid memory access that causes the crash. System administrators should ensure that all affected Linux kernel versions are updated to include this patch, particularly in virtualized environments where Xen hypervisor integration is used. Organizations should also implement monitoring for suspicious suspend/resume patterns that could indicate potential exploitation attempts, while maintaining regular kernel update schedules to address similar vulnerabilities. The fix aligns with security best practices for virtualized environments and represents a defensive programming approach that prevents invalid state transitions in concurrent systems, as recommended by the Linux kernel security guidelines and industry standards for hypervisor security.