CVE-2024-26940 is a vulnerability identified in the Linux kernel's drm/vmwgfx driver, which is responsible for managing graphics resources for VMware virtual GPU devices. The issue arises because the driver creates debugfs entries (/sys/kernel/debug/dri/0/mob_ttm) even when the corresponding ttm_resource_manager is not allocated. This improper creation leads to a kernel crash when a user or process attempts to read from these debugfs files. The root cause is the lack of a conditional check before creating debugfs entries for mob_ttm, system_mob_ttm, and gmr_ttm resources. When these resources are unallocated, accessing their debugfs entries results in a null pointer dereference or invalid memory access, causing a kernel oops and system crash. The provided stack trace shows the crash occurs in the ttm_resource_manager_debug function during a page fault triggered by reading the debugfs file. This vulnerability affects specific Linux kernel versions identified by commit hashes (af4a25bbe5e7e60ff696ef5c1ec48ab2d51c17c6). The CVSS v3.1 base score is 5.5 (medium severity), reflecting that the attack vector is local (AV:L), requires low complexity (AC:L), needs privileges (PR:L), no user interaction (UI:N), and impacts availability only (A:H) without affecting confidentiality or integrity. No known exploits are reported in the wild yet. The fix involves adding checks to ensure debugfs entries are created only when the corresponding ttm_resource_manager is allocated, preventing invalid memory access and system crashes.

For European organizations, this vulnerability primarily threatens system availability on Linux hosts running VMware virtual GPU drivers with the affected kernel versions. Systems could experience unexpected kernel panics or crashes when debugfs files are accessed, potentially leading to denial of service conditions. This can disrupt services relying on virtualized Linux environments, including cloud infrastructure, development platforms, and container hosts. Since the attack requires local privileges, the risk is higher in multi-tenant or shared environments where untrusted users or processes might trigger the crash. The impact on confidentiality and integrity is negligible, but availability degradation can affect operational continuity, especially in critical infrastructure, research institutions, and enterprises heavily dependent on Linux virtualization. The vulnerability may also complicate debugging or monitoring activities that rely on debugfs, potentially delaying incident response or system diagnostics.

European organizations should promptly apply the Linux kernel patches that address CVE-2024-26940 once available from their Linux distribution vendors or kernel maintainers. Until patched, restrict access to /sys/kernel/debug/dri/0/mob_ttm and related debugfs entries by limiting permissions to trusted administrators only. Disable or restrict debugfs mounting on production systems where possible to reduce exposure. Implement strict access controls and monitoring on systems running VMware virtual GPU drivers to detect unusual attempts to read debugfs files. For environments using virtualization, ensure that guest users do not have unnecessary privileges that could allow them to trigger this vulnerability. Regularly audit kernel versions and driver modules to identify and remediate vulnerable instances. Additionally, consider deploying kernel live patching solutions if available to minimize downtime during patch application.