CVE-2024-46698 is a vulnerability identified in the Linux kernel related to the handling of PCI devices in the video/aperture subsystem. The issue arises in the function aperture_remove_conflicting_pci_devices(), which manages the disabling of system framebuffer devices (sysfb) during device initialization. Specifically, the vulnerability occurs because sysfb_disable() is only called on VGA class devices, but the code does not properly handle cases where the primary boot display device is non-VGA. In such scenarios, a non-VGA PCI device is probed first and its resources are freed by aperture_detach_platform_device(), but sysfb_disable() is not called for it. Subsequently, when a secondary VGA class GPU device is processed, sysfb_disable() is called on it, but it attempts to access resources that have already been freed by the earlier non-VGA device. This leads to a NULL pointer dereference, causing a kernel crash (denial of service). The fix involves modifying sysfb_disable() to accept a device pointer and adding checks to ensure it only operates on appropriate devices, preventing the dereference of freed resources. Additional improvements include build fixes when CONFIG_SCREEN_INFO is not set and synchronization enhancements by moving device checks inside a mutex. This vulnerability affects specific Linux kernel versions identified by commit hashes and was published on September 13, 2024. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet.

For European organizations, this vulnerability primarily presents a risk of denial-of-service (DoS) conditions on Linux systems that use affected kernel versions, particularly those running on hardware configurations with multiple GPUs or non-VGA primary display devices. Systems that rely on Linux for critical infrastructure, servers, or embedded devices with such hardware setups could experience kernel panics leading to service interruptions. While this vulnerability does not directly lead to privilege escalation or data leakage, the resulting system crashes could disrupt business operations, especially in environments requiring high availability such as financial institutions, telecommunications, and industrial control systems. Additionally, recovery from kernel crashes may require manual intervention or system reboots, increasing operational overhead. Since the vulnerability involves low-level kernel code interacting with hardware, it may also affect virtualization hosts or cloud infrastructure nodes running Linux, potentially impacting hosted services. The absence of known exploits suggests limited immediate risk, but the vulnerability should be addressed promptly to avoid future exploitation attempts.

European organizations should prioritize updating their Linux kernels to versions that include the patch for CVE-2024-46698. Since the vulnerability is tied to specific kernel commits, applying the latest stable kernel releases from trusted Linux distributions is critical. For environments where immediate patching is not feasible, organizations should audit systems for the presence of multiple GPUs or non-VGA primary display devices and consider disabling or isolating such hardware configurations temporarily. Monitoring kernel logs for signs of NULL pointer dereferences or unexpected sysfb_disable() calls can help detect attempts to trigger the vulnerability. Additionally, implementing robust system monitoring and automated recovery mechanisms can reduce downtime caused by potential kernel crashes. Organizations should also review their hardware compatibility and kernel configuration options, such as CONFIG_SCREEN_INFO, to ensure they align with recommended settings that mitigate this issue. Finally, maintaining strong access controls and limiting user privileges can reduce the risk of exploitation attempts, even though this vulnerability does not require user interaction or authentication to trigger a crash.