CVE-2023-52817 is a high-severity vulnerability in the Linux kernel's AMDGPU driver, specifically affecting certain AMD GPU chips such as VEGA20. The flaw arises from a null pointer dereference in the drm/amdgpu component when the smc_rreg pointer is NULL. This occurs during the reading of the amdgpu_regs_smc debugfs file located at /sys/kernel/debug/dri/0. When accessed, the kernel attempts to dereference a NULL pointer, leading to a kernel oops and potential system crash. The vulnerability is triggered by a simple read operation (e.g., 'cat amdgpu_regs_smc'), which causes a null pointer access and an exception in kernel mode. The detailed kernel logs show a page fault (#PF) due to an invalid memory access at address 0x0, indicating a NULL pointer dereference. This vulnerability is classified under CWE-476 (NULL Pointer Dereference). The CVSS v3.1 score is 8.4 (high), with vector AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating that the attack vector is local, requires low attack complexity, no privileges, and no user interaction, and impacts confidentiality, integrity, and availability to a high degree. Although exploitation requires local access, the impact is severe because it can cause a denial of service via kernel crash and potentially allow privilege escalation or arbitrary code execution due to kernel memory corruption. The vulnerability affects specific Linux kernel versions containing the vulnerable AMDGPU driver code. No known exploits are currently reported in the wild, but the vulnerability is publicly disclosed and patched in recent kernel updates. The root cause is insufficient validation of the smc_rreg pointer before dereferencing it in the debugfs read handler for AMDGPU registers.

For European organizations, this vulnerability poses a significant risk primarily to systems running Linux kernels with the vulnerable AMDGPU driver and equipped with affected AMD GPUs such as VEGA20. The impact includes potential denial of service due to kernel crashes, which can disrupt critical services and operations. Furthermore, the vulnerability could be leveraged for privilege escalation or arbitrary code execution within the kernel context, threatening system confidentiality and integrity. Organizations relying on Linux-based infrastructure for servers, workstations, or embedded systems with AMD GPUs are at risk. This includes sectors such as finance, healthcare, manufacturing, and government agencies where Linux is prevalent. The local attack vector means that attackers need some form of local access, which could be obtained via compromised user accounts or insider threats. The high severity and potential for system instability or compromise make timely patching essential. Additionally, disruption caused by kernel panics could affect high-availability systems and critical infrastructure, leading to operational downtime and financial loss.

1. Immediate application of the latest Linux kernel patches that address CVE-2023-52817 is the primary mitigation step. Organizations should update their Linux distributions to versions containing the fix for the AMDGPU driver null pointer dereference. 2. Restrict access to debugfs, especially the /sys/kernel/debug/dri/0 directory and the amdgpu_regs_smc file, to trusted and authorized users only. This can be done by mounting debugfs with appropriate permissions or disabling debugfs if not required. 3. Implement strict local user access controls and monitoring to detect and prevent unauthorized attempts to read from debugfs files. 4. Employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), Kernel Page Table Isolation (KPTI), and SELinux/AppArmor policies to limit the impact of potential kernel exploits. 5. Conduct regular audits of systems with AMD GPUs to identify vulnerable kernel versions and ensure compliance with patch management policies. 6. For environments where immediate patching is not feasible, consider disabling or blacklisting the AMDGPU driver if the hardware is not in use or switching to alternative GPU drivers where possible. 7. Monitor security advisories and threat intelligence feeds for any emerging exploit attempts targeting this vulnerability to respond promptly.