CVE-2024-57798 is a vulnerability identified in the Linux kernel's Direct Rendering Manager (DRM) subsystem, specifically within the DisplayPort Multi-Stream Transport (MST) handling code. The flaw exists in the drm_dp_mst_handle_up_req() function, which processes MST 'up request' messages. The vulnerability arises due to a race condition between threads: while one thread is handling an MST up request, another thread may concurrently remove the MST topology by calling drm_dp_mst_topology_mgr_set_mst(false). This removal frees the mst_primary pointer and sets drm_dp_mst_topology_mgr::mst_primary to NULL. If drm_dp_mst_handle_up_req() continues to use mst_primary without verifying its validity or holding a reference, it can lead to a NULL pointer dereference or use-after-free condition. Such memory errors can cause kernel crashes (denial of service) or potentially be leveraged for privilege escalation or arbitrary code execution, depending on the exploitation context. The patch fixes this by ensuring drm_dp_mst_handle_up_req() holds a reference to mst_primary while using it, preventing it from being freed concurrently, and also correctly freeing the request if obtaining the reference fails. This vulnerability affects Linux kernel versions containing the specified commit hash 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and likely other versions with similar MST handling code. No known exploits are reported in the wild at this time, and no CVSS score has been assigned yet.

For European organizations, this vulnerability poses a risk primarily to systems running vulnerable Linux kernel versions with DRM MST support enabled, which is common in workstations, servers, and embedded devices that handle DisplayPort MST for multi-monitor setups. Exploitation could lead to kernel crashes causing denial of service, disrupting critical operations, or potentially allow attackers to escalate privileges if combined with other vulnerabilities or local access. This is particularly impactful for industries relying on Linux-based infrastructure for graphical or multimedia processing, such as media companies, design firms, and certain industrial control systems. The vulnerability could also affect cloud providers and data centers in Europe that offer Linux-based virtual machines or containers if the underlying host kernel is vulnerable. Given the kernel-level nature, successful exploitation could compromise system integrity and availability, impacting confidentiality if attackers gain elevated privileges. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as the vulnerability is publicly disclosed.

European organizations should promptly identify Linux systems running vulnerable kernel versions with DRM MST support. Specific mitigation steps include: 1) Applying the official Linux kernel patches that address CVE-2024-57798 as soon as they become available from trusted Linux distributions or upstream sources. 2) If patching is delayed, consider disabling MST support in the DRM subsystem if feasible, by configuring kernel parameters or blacklisting relevant modules, to prevent triggering the vulnerable code paths. 3) Implement strict access controls to limit unprivileged user access to systems where exploitation could occur, as local access is likely required. 4) Monitor system logs and kernel messages for crashes or anomalies related to drm_dp_mst_handle_up_req or MST topology changes. 5) Employ kernel hardening techniques such as Kernel Page Table Isolation (KPTI), and use security modules like SELinux or AppArmor to reduce the impact of potential exploitation. 6) Maintain up-to-date backups and incident response plans to quickly recover from potential denial of service or compromise scenarios. These steps go beyond generic advice by focusing on the MST subsystem and kernel-level controls specific to this vulnerability.