CVE-2022-48768 in Linux
Summary
by MITRE • 06/20/2024
In the Linux kernel, the following vulnerability has been resolved:
tracing/histogram: Fix a potential memory leak for kstrdup()
kfree() is missing on an error path to free the memory allocated by kstrdup():
p = param = kstrdup(data->params[i], GFP_KERNEL);
So it is better to free it via kfree(p).
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 10/29/2024
The vulnerability identified as CVE-2022-48768 resides within the Linux kernel's tracing subsystem, specifically within the histogram functionality that handles kernel trace events. This issue represents a memory management flaw that occurs during the processing of trace parameters, where the kernel fails to properly release allocated memory resources under certain error conditions. The tracing subsystem is a critical component that enables detailed monitoring and analysis of kernel activities, making this vulnerability particularly concerning for systems relying on comprehensive kernel tracing capabilities.
The technical flaw manifests in the histogram implementation where the kstrdup() function is used to duplicate string parameters from trace data, allocating memory in the kernel's address space using GFP_KERNEL flags. The allocation occurs successfully when the code processes data->params[i] into variable p, but during error path execution, the allocated memory is not properly freed through the kfree() function. This creates a memory leak that persists until the kernel terminates or the memory is reclaimed through other mechanisms, effectively wasting kernel memory resources that could be critical for system stability.
The operational impact of this vulnerability extends beyond simple memory consumption, as it can lead to progressive memory exhaustion in systems with high tracing activity or continuous kernel monitoring. When multiple trace events occur in rapid succession, each error path execution results in a memory leak, potentially causing system performance degradation, reduced responsiveness, or in extreme cases, system instability due to memory starvation. This vulnerability affects any Linux system utilizing the kernel's tracing infrastructure, particularly those implementing histogram-based trace analysis or monitoring systems that process large volumes of trace data.
Mitigation strategies for CVE-2022-48768 involve applying the official kernel patch that ensures proper memory cleanup through the addition of kfree(p) calls on error paths, preventing the memory leak from occurring. System administrators should prioritize updating their kernel versions to include this fix, particularly in production environments where kernel tracing is actively utilized. The vulnerability aligns with CWE-401, which specifically addresses improper release of memory after use, and can be categorized under ATT&CK technique T1059.006 for kernel-level code execution and memory manipulation. Organizations should also implement monitoring for unusual memory consumption patterns in systems with active tracing to detect potential exploitation of this vulnerability before it is patched.