CVE-2022-49335 is a vulnerability identified in the Linux kernel's AMD GPU driver component (amdgpu), specifically within the command submission (cs) interface. The flaw arises when a command submission with zero chunks is processed. Normally, command submissions include one or more chunks of data that the GPU driver uses to execute graphics commands. However, submitting a command with zero chunks triggers illegal behavior, leading to a kernel NULL pointer dereference and a subsequent kernel oops (crash). This occurs because the driver attempts to execute commands using an incorrect userspace driver, resulting in a supervisor read access fault at an invalid memory address (0x00000000000001d8). The kernel stack trace shows the fault happens in the amdgpu_cs_ioctl function, which handles ioctl calls for command submissions. The issue can cause the kernel to crash, leading to denial of service. The vulnerability is rooted in improper validation of the command submission input, allowing malformed requests to cause memory access violations. Although no known exploits are reported in the wild, the vulnerability is significant because it affects the Linux kernel's graphics subsystem, which is widely used in servers, desktops, and embedded devices. The affected versions are tied to a specific Linux kernel commit hash, indicating the flaw exists in certain kernel builds prior to patching. The bug is tracked in the freedesktop.org AMD GPU driver issue tracker, confirming it is recognized and addressed by the maintainers. No CVSS score is assigned yet, and no patches are linked in the provided data, but the vulnerability is publicly disclosed and classified as a kernel-level denial of service risk due to NULL pointer dereference triggered by malformed ioctl calls to the amdgpu driver.

For European organizations, this vulnerability poses a risk primarily of denial of service on Linux systems using AMD GPUs with the affected kernel versions. Systems running workloads that rely on GPU acceleration or graphical interfaces could experience kernel crashes, leading to service interruptions, potential data loss, or degraded operational capability. This is particularly critical for sectors such as finance, research, media production, and government infrastructure where Linux servers and workstations with AMD GPUs are deployed. The inability to handle malformed command submissions safely could be exploited by local users or malicious software with access to the system to cause instability. While the vulnerability does not appear to allow privilege escalation or remote code execution directly, the resulting kernel crashes could be leveraged in multi-stage attacks or disrupt critical services. European organizations with high reliance on Linux-based infrastructure, especially those using AMD GPU hardware for compute or graphical workloads, may face operational risks until the vulnerability is patched. Additionally, the disruption could impact compliance with availability requirements under regulations such as GDPR and NIS Directive if critical services are affected.

1. Immediate mitigation involves updating the Linux kernel to a version where this vulnerability is patched. Organizations should track Linux kernel releases and apply security updates promptly, especially those including fixes to the amdgpu driver. 2. If immediate patching is not feasible, restrict access to systems with AMD GPUs to trusted users only, minimizing the risk of malicious command submissions. 3. Employ kernel lockdown or mandatory access control mechanisms (e.g., SELinux, AppArmor) to limit the ability of unprivileged users or processes to invoke ioctl calls on the amdgpu device nodes. 4. Monitor system logs for kernel oops or crashes related to amdgpu_cs_ioctl to detect potential exploitation attempts. 5. For critical environments, consider temporarily disabling or blacklisting the amdgpu driver if GPU functionality is not essential, to prevent the vulnerability from being triggered. 6. Engage with Linux distribution security advisories and AMD GPU driver maintainers for official patches and guidance. 7. Conduct thorough testing of kernel updates in staging environments to ensure stability before deployment in production.