CVE-2024-50260 is a vulnerability identified in the Linux kernel, specifically within the sock_map subsystem. The issue arises from a race condition that can lead to a NULL pointer dereference in the function sock_map_link_update_prog(). This occurs when sock_map_link_detach() sets the sockmap_link->map pointer to NULL while holding a mutex (sockmap_mutex), and shortly thereafter, sock_map_link_update_prog() attempts to access this pointer without verifying if it is NULL. The race condition involves concurrent locking and unlocking of the mutex, which can cause the update function to dereference a NULL pointer, potentially leading to a kernel crash (denial of service) or other undefined behavior. The root cause is the lack of a NULL pointer check before accessing the sockmap_link->map in the update function. The fix implemented involves adding a NULL pointer check to prevent updates on links that are in the process of being released, thereby eliminating the race condition and preventing the NULL pointer dereference. This vulnerability affects specific Linux kernel versions identified by the commit hash 699c23f02c65cbfc3e638f14ce0d70c23a2e1f02. No known exploits are reported in the wild as of the publication date (November 9, 2024). The vulnerability does not have an assigned CVSS score yet.

For European organizations, the primary impact of CVE-2024-50260 is the potential for denial of service (DoS) on Linux systems running affected kernel versions. Since the vulnerability can cause kernel crashes due to NULL pointer dereferences, critical infrastructure, servers, and network devices relying on Linux could experience unexpected downtime. This could disrupt business operations, especially in sectors with high Linux adoption such as telecommunications, finance, cloud service providers, and public sector IT infrastructure. Although the vulnerability does not appear to allow privilege escalation or remote code execution, the induced instability could be exploited by attackers to cause service interruptions. Given the widespread use of Linux in Europe, particularly in enterprise environments and cloud platforms, the risk of operational impact is significant if unpatched systems are exposed. However, the lack of known exploits and the requirement for specific kernel versions somewhat limits immediate risk. Organizations with robust patch management and kernel update policies will be less affected.

European organizations should prioritize updating their Linux kernels to versions that include the fix for CVE-2024-50260. Since the vulnerability stems from a race condition in the sock_map subsystem, applying the official patch or upgrading to a kernel version that incorporates the fix is the most effective mitigation. Beyond patching, organizations should audit their use of the sock_map feature, especially in environments using advanced networking features such as eBPF programs that interact with socket maps. Limiting access to kernel-level features and ensuring that only trusted code can manipulate sock_map links will reduce the attack surface. Additionally, monitoring kernel logs for unusual crashes or OOPS messages related to sock_map can help detect attempts to trigger this vulnerability. For critical systems where immediate patching is not feasible, consider isolating affected hosts from untrusted networks and restricting user privileges to prevent exploitation attempts. Finally, maintain an up-to-date inventory of Linux kernel versions in use across the organization to quickly identify and remediate vulnerable systems.