CVE-2019-19057 in Linux
Summary
by MITRE
Two memory leaks in the mwifiex_pcie_init_evt_ring() function in drivers/net/wireless/marvell/mwifiex/pcie.c in the Linux kernel through 5.3.11 allow attackers to cause a denial of service (memory consumption) by triggering mwifiex_map_pci_memory() failures, aka CID-d10dcb615c8e.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/23/2024
The vulnerability identified as CVE-2019-19057 represents a critical memory management issue within the Linux kernel's wireless networking subsystem, specifically affecting the marvell mwifiex driver component. This flaw exists in the mwifiex_pcie_init_evt_ring() function located in drivers/net/wireless/marvell/mwifiex/pcie.c and impacts kernel versions through 5.3.11. The vulnerability manifests as two distinct memory leaks that occur when the mwifiex_map_pci_memory() function fails during the initialization process of PCIe event rings. These memory leaks directly contribute to progressive memory consumption within the system, ultimately leading to potential denial of service conditions that can severely impact system stability and performance.
The technical implementation of this vulnerability stems from inadequate error handling within the PCIe initialization sequence of the marvell wireless driver. When mwifiex_map_pci_memory() encounters failures during memory mapping operations, the function fails to properly release previously allocated memory resources, resulting in memory leaks that accumulate over time. The CWE-401 classification applies here as this represents a classic memory leak scenario where allocated memory is not properly deallocated, and the vulnerability operates at the kernel level where such issues can have severe systemic implications. The flaw specifically affects the PCIe event ring initialization process, which is fundamental to proper communication between the wireless hardware and the kernel's networking stack.
From an operational perspective, this vulnerability creates a significant risk for systems running affected kernel versions, particularly those in server or embedded environments where continuous operation is critical. Attackers can exploit this weakness by repeatedly triggering the mwifiex_map_pci_memory() failure conditions, causing the system to gradually consume available memory resources until system performance degrades or complete system exhaustion occurs. The impact extends beyond simple resource consumption as the memory leaks can affect overall system stability, potentially causing crashes or making the system unresponsive to legitimate network traffic. This vulnerability directly maps to the ATT&CK technique T1499.004 which involves network denial of service attacks through resource exhaustion.
The mitigation strategies for CVE-2019-19057 primarily involve upgrading to kernel versions that contain the patched implementation of the mwifiex driver. The fix addresses the improper memory management by ensuring that all allocated resources are properly released when mwifiex_map_pci_memory() operations fail. System administrators should prioritize patching affected systems, particularly those running kernel versions 5.3.11 or earlier, as the vulnerability can be exploited remotely through wireless network traffic. Additionally, monitoring system memory usage and implementing automated alerting for unusual memory consumption patterns can help detect exploitation attempts. Organizations should also consider implementing network segmentation to limit potential attack surfaces and ensure that wireless network components are properly isolated from critical system resources to minimize the impact of such vulnerabilities.