CVE-2019-19077 in Linux
Summary
by MITRE
A memory leak in the bnxt_re_create_srq() function in drivers/infiniband/hw/bnxt_re/ib_verbs.c in the Linux kernel through 5.3.11 allows attackers to cause a denial of service (memory consumption) by triggering copy to udata failures, aka CID-4a9d46a9fe14.
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-2019-19077 represents a critical memory management flaw within the Linux kernel's InfiniBand hardware driver implementation. This issue specifically affects the bnxt_re driver, which provides support for BlueNexus network adapters in high-performance computing environments. The vulnerability manifests as a memory leak in the bnxt_re_create_srq() function, which is responsible for creating shared receive queues within the InfiniBand communication framework. The flaw occurs when the driver encounters copy to user data failures during the creation process, leading to improper memory deallocation and subsequent resource exhaustion.
The technical exploitation of this vulnerability exploits a fundamental flaw in the kernel's memory management routines where allocated memory structures are not properly released when error conditions occur during the udata copy operations. This memory leak directly impacts the system's ability to maintain sufficient available memory for legitimate operations, as the kernel's memory pool gradually becomes depleted through repeated exploitation attempts. The vulnerability is particularly dangerous in high-throughput environments where InfiniBand communication is heavily utilized, as the memory consumption can escalate rapidly and lead to complete system instability or unresponsiveness.
From an operational perspective, this vulnerability creates a significant denial of service risk that can be exploited by malicious actors with local access to the system. The attack vector requires minimal privileges and can be executed repeatedly to consume system memory resources, potentially leading to system crashes or forced reboots. The impact extends beyond simple resource exhaustion as the memory leak can affect other kernel subsystems that depend on the available memory pool, creating cascading failures that compromise overall system stability. This vulnerability directly relates to CWE-401, which describes improper handling of memory allocation failures in kernel space, and aligns with ATT&CK technique T1499.004 for network denial of service attacks that target system resources.
The recommended mitigation strategies include applying the latest kernel security patches that address the memory leak in the bnxt_re_create_srq() function, implementing memory monitoring and alerting mechanisms to detect unusual memory consumption patterns, and restricting local access to systems running affected kernel versions. Organizations should also consider implementing resource limits and monitoring for InfiniBand related processes to prevent exploitation from escalating to system-wide denial of service conditions. Additionally, network administrators should monitor for unusual memory usage patterns and implement automated response procedures that can isolate affected systems when memory consumption exceeds predetermined thresholds, ensuring that the vulnerability cannot be leveraged to create persistent denial of service conditions within the network infrastructure.