CVE-2019-19045 in Linux
Summary
by MITRE
A memory leak in the mlx5_fpga_conn_create_cq() function in drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c in the Linux kernel before 5.3.11 allows attackers to cause a denial of service (memory consumption) by triggering mlx5_vector2eqn() failures, aka CID-c8c2a057fdc7.
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Analysis
by VulDB Data Team • 02/23/2024
The vulnerability identified as CVE-2019-19045 represents a critical memory management flaw within the Linux kernel's Mellanox ConnectX-5 FPGA driver component. This issue resides in the mlx5_fpga_conn_create_cq() function located at drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c, affecting kernel versions prior to 5.3.11. The flaw manifests as a memory leak that occurs when the mlx5_vector2eqn() function fails during execution, creating a condition where allocated memory resources are not properly released back to the system. This particular vulnerability demonstrates the dangerous consequences of improper resource management in kernel space components, where even minor failure conditions can lead to significant system instability.
The technical mechanism underlying this vulnerability involves the failure path of the FPGA connection creation process within the Mellanox driver subsystem. When mlx5_vector2eqn() encounters an error condition during its execution, the memory allocation performed by mlx5_fpga_conn_create_cq() is not properly deallocated, resulting in gradual memory consumption over time. This memory leak occurs because the driver does not implement proper error handling to ensure resource cleanup when intermediate operations fail, creating a scenario where each failed connection attempt consumes additional memory without subsequent release. The vulnerability specifically targets the Mellanox ConnectX-5 FPGA driver's connection management functionality, which is part of the broader mlx5 core driver infrastructure that provides network connectivity for high-performance computing environments.
The operational impact of this vulnerability extends beyond simple resource exhaustion, potentially leading to complete system denial of service conditions. Attackers can exploit this weakness by repeatedly triggering mlx5_vector2eqn() failures, causing progressive memory consumption that eventually depletes available system resources. This type of attack is particularly concerning in production environments where high availability is critical, as it can render systems unusable without requiring elevated privileges or complex exploitation techniques. The vulnerability affects systems utilizing Mellanox ConnectX-5 network adapters with FPGA capabilities, making it relevant to data centers, high-performance computing clusters, and enterprise networking infrastructure where these adapters are commonly deployed. The memory leak can accumulate over time, potentially causing system instability, application crashes, or complete system hangs when memory resources become exhausted.
Mitigation strategies for CVE-2019-19045 primarily focus on kernel version upgrades to 5.3.11 or later, which contain the necessary patches to address the improper resource cleanup in the mlx5_fpga_conn_create_cq() function. System administrators should prioritize applying these kernel updates across all affected systems, particularly in environments where Mellanox ConnectX-5 adapters are utilized. Additionally, monitoring system memory consumption patterns can help detect potential exploitation attempts, though this represents a reactive approach rather than a preventive solution. The vulnerability aligns with CWE-401, which categorizes memory leaks as a common weakness in software development, and can be mapped to ATT&CK technique T1499.004 for resource exhaustion attacks, highlighting the broader threat landscape where such memory management flaws can be leveraged for denial of service operations. Organizations should also consider implementing network segmentation and access controls to limit potential exploitation vectors while awaiting patch deployment.