CVE-2019-19047 in Linux
Summary
by MITRE
A memory leak in the mlx5_fw_fatal_reporter_dump() function in drivers/net/ethernet/mellanox/mlx5/core/health.c in the Linux kernel before 5.3.11 allows attackers to cause a denial of service (memory consumption) by triggering mlx5_crdump_collect() failures, aka CID-c7ed6d0183d5.
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Analysis
by VulDB Data Team • 02/23/2024
The vulnerability identified as CVE-2019-19047 represents a critical memory management flaw within the Linux kernel's Mellanox mlx5 network driver subsystem. This issue specifically targets the mlx5_fw_fatal_reporter_dump() function located in drivers/net/ethernet/mellanox/mlx5/core/health.c, where improper memory handling leads to persistent resource consumption. The vulnerability affects Linux kernel versions prior to 5.3.11, making it a significant concern for systems utilizing Mellanox ConnectX series network adapters that rely on the mlx5 driver for their operation.
The technical exploitation of this vulnerability occurs through the manipulation of mlx5_crdump_collect() function failures, which triggers the memory leak condition within the health reporting mechanism of the mlx5 driver. When the system encounters certain error conditions during firmware crash dump collection, the mlx5_fw_fatal_reporter_dump() function fails to properly release allocated memory resources, resulting in gradual memory consumption that can ultimately lead to system instability. This memory leak is particularly dangerous because it occurs within the kernel space where the driver operates, making it difficult to detect and mitigate through conventional user-space mechanisms. The flaw demonstrates characteristics consistent with CWE-401, which specifically addresses memory leaks in software systems.
The operational impact of this vulnerability extends beyond simple resource exhaustion, as it can severely compromise system availability and performance for network-intensive applications. Attackers can systematically consume memory resources by repeatedly triggering the conditions that cause mlx5_crdump_collect() failures, leading to progressive degradation of system performance or complete denial of service. This type of attack aligns with ATT&CK technique T1499.001, which covers network denial of service attacks through resource exhaustion. The vulnerability particularly affects systems running Mellanox network adapters in high-throughput environments where the driver is frequently invoked, making it a significant concern for data centers, cloud infrastructure, and enterprise network deployments.
Mitigation strategies for CVE-2019-19047 primarily focus on kernel version upgrades to 5.3.11 or later, where the memory leak has been addressed through proper resource management within the mlx5 driver. System administrators should prioritize patching affected systems, particularly those running production environments with Mellanox network hardware. Additionally, implementing monitoring solutions that track memory usage patterns and system resource consumption can help detect anomalous behavior indicative of this vulnerability being exploited. Organizations should also consider implementing network segmentation and access controls to limit potential attack vectors that could trigger the vulnerable code paths, while maintaining regular security assessments to identify other potential memory management issues within kernel modules. The fix implemented in the patched kernel versions demonstrates proper memory deallocation practices that prevent the accumulation of unreleased memory segments during error handling scenarios.