CVE-2024-41092 is a use-after-free (UAF) vulnerability in the Linux kernel's Intel i915 graphics driver, specifically within the Direct Rendering Manager (DRM) component handling GPU fence registers. The flaw arises in the function i915_vma_revoke_fence(), which is responsible for revoking fence registers associated with GPU virtual memory areas (VMAs). The vulnerability is caused by a race condition between revocation of fence registers and the asynchronous execution of signal callbacks triggered upon completion of GPU requests that use these fences. This race can lead to the kernel attempting to access or manipulate fence objects that have already been freed, resulting in a use-after-free scenario. The issue was introduced due to a change in the kernel where the function stopped waiting for the fence's active state to become idle before revocation, relying instead on fence_write() without proper synchronization. This leads to kernel crashes (BUGs) and invalid opcode exceptions, as observed in continuous integration (CI) test failures on Intel Alder Lake platforms and similar hardware. The fix involves reintroducing a wait for the fence's active state to become idle before revocation, ensuring safe fence handling and preventing use-after-free conditions. This vulnerability affects Linux kernel versions containing the problematic commit 0d86ee35097a and related builds. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, this vulnerability poses a risk primarily to systems running Linux kernels with the affected i915 driver versions on Intel Alder Lake and similar platforms. The impact includes potential kernel crashes leading to system instability or denial of service (DoS). In environments where Linux is used for critical infrastructure, servers, or workstations with Intel integrated graphics, this could disrupt operations, cause data loss, or require unscheduled downtime for patching and recovery. Although the vulnerability does not directly enable privilege escalation or remote code execution, the kernel panic and system instability could be leveraged by attackers to cause persistent DoS conditions or to facilitate further attacks in complex threat scenarios. Organizations relying on Linux-based desktop or server systems with Intel graphics in sectors such as finance, manufacturing, research, and government could be affected. The lack of known exploits reduces immediate risk, but the presence of a kernel-level UAF vulnerability necessitates prompt attention to avoid exploitation as attackers develop techniques targeting this flaw.

European organizations should prioritize updating their Linux kernels to versions that include the fix for CVE-2024-41092. This involves applying the patch that waits for the fence's active state to become idle before revocation in the i915 driver. System administrators should monitor vendor advisories and Linux distribution security updates for patched kernel releases. For environments where immediate patching is not feasible, organizations can consider temporarily disabling or limiting the use of Intel integrated graphics features that rely on the affected fence handling, if operationally acceptable. Additionally, enabling kernel lockdown features and restricting unprivileged access to GPU interfaces can reduce attack surface. Continuous monitoring of system logs for i915-related kernel errors or crashes can help detect exploitation attempts or instability. Testing patches in staging environments before deployment is recommended to ensure compatibility and stability. Finally, maintaining robust backup and recovery procedures will mitigate impact from potential system crashes caused by this vulnerability.