CVE-2024-41006 addresses a memory leak vulnerability in the Linux kernel's netrom protocol implementation, specifically within the nr_heartbeat_expiry() function. The netrom protocol is a networking protocol used primarily for amateur radio packet networks. The vulnerability was identified through syzbot, an automated kernel fuzzing tool, which reported a memory leak in the nr_create() function. The root cause stems from incorrect reference counting management related to socket states and flags. In particular, the patch fixed an issue where sock_hold() was called on a socket with the SOCK_DESTROY flag set, even though the file descriptor had already been closed and nr_release() had been called. This led to a memory leak because the reference count was unnecessarily incremented without a corresponding decrement, preventing proper resource cleanup. The fix ensures sock_hold() is only called for listening sockets with the SOCK_DEAD flag, where it is appropriate to maintain the reference count. The vulnerability involves complex state transitions of the netrom socket states (NR_STATE_0, NR_STATE_2, NR_STATE_3) and the handling of socket flags (SOCK_DESTROY and SOCK_DEAD) during connection establishment, heartbeat expiry, and socket release. Although the vulnerability does not appear to allow direct code execution or privilege escalation, the memory leak could degrade system stability over time, especially on systems heavily utilizing the netrom protocol. The affected versions include multiple Linux kernel commits prior to the fix, and the issue was responsibly disclosed by InfoTeCS on behalf of the Linux Verification Center using Syzkaller. There are no known exploits in the wild at this time, and no CVSS score has been assigned yet.

For European organizations, the impact of CVE-2024-41006 is primarily related to system reliability and availability rather than direct compromise of confidentiality or integrity. Organizations running Linux systems with netrom protocol support—often niche or specialized environments such as amateur radio networks, research institutions, or certain industrial control systems—may experience memory leaks leading to resource exhaustion. Over time, this could cause degraded performance, system crashes, or forced reboots, impacting operational continuity. While the netrom protocol is not widely used in mainstream enterprise environments, certain sectors in Europe with specialized communication needs (e.g., emergency services, research labs, or hobbyist communities) could be affected. The vulnerability does not appear to facilitate remote code execution or privilege escalation, limiting its use as an attack vector for broader cyberattacks. However, persistent memory leaks can be exploited by attackers to cause denial-of-service conditions, which could disrupt critical services. Given the Linux kernel's widespread use across European infrastructure, ensuring all kernel components are patched is essential to maintain system stability and security.

1. Apply the official Linux kernel patch that addresses CVE-2024-41006 as soon as it becomes available in your distribution's kernel updates. 2. For organizations using custom or embedded Linux kernels with netrom support, backport the fix from the relevant commit (409db27e3a2e) to ensure the memory leak is resolved. 3. Monitor systems running netrom protocol for unusual memory usage patterns or resource exhaustion symptoms that could indicate the presence of this memory leak. 4. Limit or disable netrom protocol usage if it is not required, reducing the attack surface and exposure to this vulnerability. 5. Implement robust system monitoring and alerting to detect early signs of memory leaks or socket resource mismanagement. 6. Conduct regular kernel updates and vulnerability assessments to ensure all known issues are addressed promptly. 7. Engage with Linux kernel maintainers or community forums for additional guidance on mitigating netrom-related vulnerabilities in specialized environments.