CVE-2022-50550 is a medium-severity vulnerability in the Linux kernel, classified under the Common Weakness Enumeration (CWE) as CWE-401. This vulnerability allows for a memory leak during the initialization of disk devices, particularly when the function add_disk() fails due to invalid parameters. The kernel's handling of these failures can lead to resource exhaustion, potentially impacting system availability.
The vulnerability has a CVSS score of 5.5, indicating a medium severity level. Exploitation of this vulnerability is possible in a local context, requiring low privileges and no user interaction. The attack complexity is low, making it a considerable risk for organizations running affected versions of the Linux kernel.
The immediate risk to organizations includes potential downtime and degraded system performance due to memory leaks. Organizations should prioritize patching this vulnerability to ensure reliability and maintain service availability.
Currently, there are no known exploits in the wild for this vulnerability, but organizations should remain vigilant and implement the necessary patches as soon as they are available.
Organizations should prioritize patching immediately.
Vulnerability Details
In the Linux kernel, the following vulnerability has been resolved: blk-iolatency: Fix memory leak on add_disk() failures When a gendisk is successfully initialized but add_disk() fails such as when a loop device has invalid number of minor device numbers specified, blkcg_init_disk() is called during init and then blkcg_exit_disk() during error handling. Unfortunately, iolatency gets initialized in the former but doesn't get cleaned up in the latter. This is because, in non-error cases, the cleanup is performed by del_gendisk() calling rq_qos_exit(), the assumption being that rq_qos policies, iolatency being one of them, can only be activated once the disk is fully registered and visible. That assumption is true for wbt and iocost, but not so for iolatency as it gets initialized before add_disk() is called. It is desirable to lazy-init rq_qos policies because they are optional features and add to hot path overhead once initialized - each IO has to walk all the registered rq_qos policies. So, we want to switch iolatency to lazy init too. However, that's a bigger change. As a fix for the immediate problem, let's just add an extra call to rq_qos_exit() in blkcg_exit_disk(). This is safe because duplicate calls to rq_qos_exit() become noop's.
Technical Analysis
The root cause of this vulnerability stems from the improper cleanup of resources during error handling in the Linux kernel's disk subsystem. Specifically, when the initialization of a disk fails, the existing implementation does not adequately release the resources allocated for iolatency, leading to a memory leak.
The attack vector is local, meaning that an attacker must have local access to the system to exploit this vulnerability. The attack complexity is low, as it does not require sophisticated techniques to exploit the vulnerability. With low privileges required and no user interaction needed, this vulnerability can be easily exploited by an unprivileged user.
In terms of impact, confidentiality and integrity are unaffected, but availability can be significantly impacted. The high availability impact means that systems may experience downtime or performance issues, affecting overall service delivery.
Risk & Impact Analysis
The real-world deployment risk associated with CVE-2022-50550 is notable, particularly for organizations that rely on the Linux kernel for critical operations. As the kernel serves as the backbone for many systems, including servers and embedded devices, the potential for exploitation could lead to significant downtime and resource wastage.
The blast radius for this vulnerability can be extensive, affecting any system running the vulnerable versions of the Linux kernel. Organizations should assess their environments and prioritize remediation efforts accordingly.
Given the CVSS score of 5.5, organizations should address this vulnerability in their priority patch cycle. The low EPSS score indicates that while exploitation may not be imminent, the risk remains significant, warranting timely action.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The following versions of the Linux kernel are affected by CVE-2022-50550: - Linux kernel versions 4.19 through 6.0.16 - Linux kernel versions 6.1 through 6.1.1 Organizations should upgrade to the latest patched versions to mitigate this vulnerability.
Mitigation & Remediation
To remediate this vulnerability, organizations should apply the latest patches provided by the Linux kernel maintainers. If immediate patching is not feasible, consider implementing the following workarounds: 1. Monitor system resource usage to detect signs of memory leaks. 2. Implement network controls to limit access to potentially vulnerable systems. 3. Regularly review system logs for anomalies. For a comprehensive approach to vulnerability management, organizations can consider engaging in penetration testing to identify and remediate vulnerabilities.
Detection Guidance
Organizations should monitor their systems for the following indicators: - Log entries that indicate memory allocation failures or excessive resource consumption. - Unusual patterns in disk I/O that may suggest exploitation attempts. - Anomalies in system performance, particularly after disk initialization operations.
AppSecure Threat Intelligence Insight
The significance of CVE-2022-50550 lies in its potential impact on system availability. As organizations increasingly rely on the Linux kernel for critical infrastructure, vulnerabilities like this highlight the need for robust patch management processes. Additionally, the low EPSS score suggests that while immediate exploitation is unlikely, the underlying issues can represent a trend in system vulnerabilities that require ongoing attention. Security teams should learn from such vulnerabilities to enhance their resilience against similar incidents in the future. For further reading on vulnerability management best practices, consider reviewing the following resources:
vulnerability management program design, penetration testing methodology, and cloud security assessment practices to bolster overall 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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