CVE-2022-49671 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
RDMA/cm: Fix memory leak in ib_cm_insert_listen
cm_alloc_id_priv() allocates resource for the cm_id_priv. When cm_init_listen() fails it doesn't free it, leading to memory leak.
Add the missing error unwind.
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Analysis
by VulDB Data Team • 06/12/2025
The vulnerability identified as CVE-2022-49671 represents a critical memory leak within the Linux kernel's RDMA (Remote Direct Memory Access) communication management subsystem. This flaw exists in the ib_cm_insert_listen function which handles the insertion of listening connection management entries within the RDMA communication framework. The issue specifically impacts the kernel's handling of resource allocation and deallocation processes, creating a persistent memory consumption problem that can degrade system performance over time. The vulnerability affects systems utilizing RDMA hardware and network communication protocols, particularly those implementing InfiniBand or RoCE (RDMA over Converged Ethernet) technologies.
The technical root cause of this memory leak stems from improper error handling within the RDMA communication management code. When cm_alloc_id_priv() function successfully allocates memory resources for cm_id_priv structures, subsequent failure in cm_init_listen() function does not trigger the necessary cleanup routine to release these allocated resources. This creates a resource management gap where allocated memory remains unreleased even when the initialization process fails. The missing error unwind mechanism prevents the system from properly deallocating the memory that was allocated during the failed initialization attempt, resulting in a gradual accumulation of unreleased memory fragments. This pattern of resource allocation without proper cleanup violates fundamental memory management principles and represents a classic example of resource leak vulnerabilities.
The operational impact of this vulnerability extends beyond simple memory consumption issues to potentially compromise system stability and performance. As the memory leak accumulates over time, it can lead to progressive memory exhaustion, particularly on systems with limited RAM resources or those running long-lived RDMA applications. The vulnerability affects systems where RDMA communication is actively used, including high-performance computing clusters, data center networks, and enterprise server environments that rely on RDMA for low-latency network communication. Attackers could potentially exploit this memory leak to cause denial of service conditions by forcing systems to consume excessive memory resources, leading to system instability or complete service disruption. The vulnerability is particularly concerning in environments where RDMA services are critical for business operations, as the memory leak could accumulate to the point of system crash or resource starvation.
Mitigation strategies for CVE-2022-49671 should focus on applying the official kernel patch that implements the missing error unwind mechanism in the ib_cm_insert_listen function. This patch ensures that when cm_init_listen() fails, the previously allocated cm_id_priv resources are properly deallocated, preventing the memory leak from occurring. System administrators should prioritize updating their kernel versions to include this fix, particularly in production environments where RDMA services are actively deployed. Additionally, monitoring systems should be implemented to track memory usage patterns and detect potential memory leak accumulation before it reaches critical levels. Organizations should also consider implementing resource limits and memory monitoring tools to detect abnormal memory consumption patterns that could indicate the presence of this vulnerability. The fix aligns with security best practices for resource management and follows established patterns for error handling in kernel space programming, addressing the underlying CWE-401 vulnerability category related to memory leaks. This vulnerability demonstrates the importance of proper error handling and resource cleanup in kernel-level code, as outlined in various security frameworks including the ATT&CK matrix's system hardening principles and kernel security best practices.