CVE-2022-48767 in Linux
Summary
by MITRE • 06/20/2024
In the Linux kernel, the following vulnerability has been resolved:
ceph: properly put ceph_string reference after async create attempt
The reference acquired by try_prep_async_create is currently leaked. Ensure we put it.
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Analysis
by VulDB Data Team • 09/29/2025
The vulnerability CVE-2022-48767 represents a memory management flaw in the Linux kernel's Ceph file system implementation that falls under the category of resource leak vulnerabilities. This issue specifically affects the ceph_string reference handling during asynchronous file creation operations within the Ceph distributed storage system. The problem manifests when the try_prep_async_create function acquires a reference to a ceph_string object but fails to properly release it afterward, creating a situation where memory resources remain allocated indefinitely. This type of vulnerability is classified as a CWE-404: Improper Resource Release or Transfer, which directly impacts the system's ability to manage memory efficiently and can lead to progressive resource exhaustion over time. The Ceph storage system, widely used in enterprise environments for its scalability and performance characteristics, becomes vulnerable to memory consumption issues that could degrade system performance or potentially cause system instability.
The technical implementation of this vulnerability occurs within the kernel's Ceph file system driver where asynchronous file creation operations are handled. When a client attempts to create a file asynchronously through the Ceph interface, the system calls try_prep_async_create to prepare the necessary data structures and acquire references to ceph_string objects that represent file paths and metadata. The flaw lies in the code path where this reference is acquired but not subsequently released through proper put operations. This creates a reference counting issue where the ceph_string object remains in memory even though it is no longer needed by the current operation. The improper reference management follows the pattern of CWE-404 where resources are acquired but not properly released, leading to memory leaks that accumulate over time as more asynchronous file creation operations occur. The vulnerability is particularly concerning because it affects the kernel space operations where memory management is critical for system stability and performance.
The operational impact of CVE-2022-48767 extends beyond simple memory consumption issues to potentially affect system reliability and performance in production environments. As the memory leak accumulates through repeated asynchronous file creation operations, the system may experience progressive degradation in performance due to reduced available memory for other kernel operations. In high-usage environments where Ceph file systems are actively serving numerous concurrent file creation requests, this memory leak could eventually lead to system instability or memory exhaustion conditions that might cause the kernel to become unresponsive or trigger out-of-memory killer mechanisms. The vulnerability is particularly relevant in cloud infrastructure environments and large-scale distributed systems where Ceph is commonly deployed as a storage backend, as these environments often involve high volumes of file I/O operations that would quickly expose the memory leak characteristics of this vulnerability. The issue aligns with ATT&CK technique T1490: Inhibit System Recovery, as the memory exhaustion could contribute to system availability issues that prevent normal operation.
The mitigation for CVE-2022-48767 involves implementing proper reference counting in the kernel module by ensuring that all ceph_string references acquired through try_prep_async_create are properly released using the corresponding put operation. This requires modifying the code path to include proper cleanup logic that executes regardless of whether the asynchronous creation attempt succeeds or fails. The fix follows standard kernel memory management practices that emphasize the principle of acquire-release pairs for all resource management operations. System administrators should apply the kernel patches that address this vulnerability as soon as they become available, particularly in production environments where Ceph storage is actively used. Organizations should also monitor their systems for memory usage patterns that might indicate the presence of this vulnerability before patching, as the memory leak may not be immediately apparent but could manifest as progressive performance degradation over time. The fix directly addresses the root cause by ensuring that the reference counting mechanism functions correctly, thereby preventing the accumulation of unreleased ceph_string objects that would otherwise consume kernel memory resources indefinitely.