CVE-2024-50215 in Linux
Summary
by MITRE • 11/09/2024
In the Linux kernel, the following vulnerability has been resolved:
nvmet-auth: assign dh_key to NULL after kfree_sensitive
ctrl->dh_key might be used across multiple calls to nvmet_setup_dhgroup() for the same controller. So it's better to nullify it after release on error path in order to avoid double free later in nvmet_destroy_auth().
Found by Linux Verification Center (linuxtesting.org) with Svace.
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Analysis
by VulDB Data Team • 10/02/2025
The vulnerability identified as CVE-2024-50215 affects the Linux kernel's NVMe over Fabrics target authentication subsystem, specifically within the nvmet-auth module. This issue represents a potential double free condition that could lead to system instability or privilege escalation. The vulnerability was discovered through automated analysis by the Linux Verification Center using the Svace static analysis tool, highlighting the importance of systematic code review processes in identifying memory management flaws in kernel space components. The NVMe over Fabrics target implementation handles authentication for remote storage connections, making this vulnerability particularly significant for enterprise storage environments where NVMe-oF is commonly deployed.
The technical flaw stems from improper memory management within the nvmet_setup_dhgroup() function where the controller's dh_key pointer is not properly nullified after being freed through kfree_sensitive() on error paths. The controller structure maintains a dh_key field that may be utilized across multiple invocations of the dhgroup setup function for the same controller instance. When an error occurs during the setup process, the memory associated with dh_key is freed but the pointer remains pointing to the freed memory location. This creates a scenario where subsequent calls to nvmet_destroy_auth() may attempt to free the same memory region again, resulting in a double free condition that can corrupt kernel memory structures and potentially enable arbitrary code execution.
The operational impact of this vulnerability extends beyond simple memory corruption, as it could allow authenticated attackers with access to NVMe over Fabrics target services to exploit the double free condition for privilege escalation or system compromise. The vulnerability affects systems running Linux kernels that implement NVMe over Fabrics target functionality, particularly those managing storage connections through RDMA or TCP transports. Given that NVMe-oF is increasingly deployed in data center environments, cloud infrastructure, and high-performance computing scenarios, the potential attack surface is substantial. The issue demonstrates how seemingly minor memory management oversights in kernel code can create significant security risks, especially when dealing with authentication and cryptographic key handling operations.
Mitigation strategies for CVE-2024-50215 should prioritize applying the official kernel patch that ensures proper nullification of the dh_key pointer after memory release on error paths. System administrators should monitor kernel update schedules and apply patches promptly, particularly in production environments where NVMe over Fabrics targets are actively used. The fix aligns with security best practices for memory management in kernel space, specifically addressing CWE-415 which covers double free conditions in software. Organizations should also consider implementing additional monitoring for anomalous system behavior that might indicate memory corruption, though such detection is challenging in kernel space. Network segmentation and access control measures can help reduce the attack surface by limiting who can establish connections to NVMe-oF target services, while regular security audits of kernel components should be part of comprehensive vulnerability management programs. This vulnerability serves as a reminder of the critical importance of thorough code review processes, especially for cryptographic and authentication-related kernel modules that handle sensitive data and maintain persistent connections.