Unlimited Package Queueing Vulnerability in xen/netback

Kernel Updated 02 Oct 2025

Summary

27/12/2021

Disclosed on

N/A

Severity

No i

Fix available

Unrated

Severity

Not published

CVSS Score

GSD-2021-1002681: xen/netback: don't queue unlimited number of packages. Affects Kernel versions >= f48da8b14d04ca87ffcffe68829afd45f926ec6a, < 0d99b3c6bd39a0a023e972d8f912fd47698bbbb8. No fix is published. How to fix ↓

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Background

The xen/netback package is a component of the Linux Kernel that provides network backend support for Xen virtualization. It allows virtual machines to communicate with the physical network infrastructure. The package is responsible for handling network traffic and queuing packets for processing. However, a vulnerability has been discovered in the package that allows an unlimited number of packages to be queued, potentially leading to resource exhaustion and denial of service.

Vulnerability Detail

The vulnerability in xen/netback arises from the package's failure to limit the number of packages that can be queued. This allows an attacker to send a large number of packets to a virtual machine, overwhelming the system and causing it to become unresponsive. The impact of this vulnerability can range from a temporary disruption of network connectivity to a complete denial of service. The vulnerability was introduced in version v3.18 of the Linux Kernel and has been fixed in version v5.4.168.

How To Fix

No fixed version is published for this vulnerability.

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Workaround

If updating the Linux Kernel is not immediately feasible, a temporary workaround can be implemented by applying a patch that limits the number of packages that can be queued in xen/netback. The patch can be obtained from the official Linux Kernel repository and applied to the affected system. However, it is strongly recommended to update to the latest kernel version as soon as possible to ensure comprehensive vulnerability mitigation.

Conclusion

The unlimited package queueing vulnerability in xen/netback can lead to resource exhaustion and denial of service. It is crucial to update the Linux Kernel to version v5.4.168 or later to mitigate this vulnerability. If immediate kernel update is not possible, applying the provided patch can serve as a temporary workaround. For further support on vulnerability remediation, please contact DevNack.com.

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