CVE-2024-46821 is a vulnerability identified in the Linux kernel, specifically within the Direct Rendering Manager (DRM) subsystem for AMD graphics hardware power management (pm). The flaw involves a negative array index read in the code handling the clk_index parameter used to index into the pptable->DpmDescriptor array. This improper handling allows negative values to be used as array indices, which can lead to out-of-bounds memory access. The vulnerability was addressed by correcting the logic to prevent negative clk_index values from being used and fixing the clk_index return check. Such a vulnerability could potentially lead to memory corruption, which might be exploited to cause system instability, crashes, or potentially escalate privileges if an attacker can manipulate the kernel memory. The vulnerability affects specific Linux kernel versions identified by the commit hash 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The fix was contributed by Tim Huang and is part of the ongoing maintenance of the Linux kernel's AMD DRM power management code.

For European organizations, the impact of CVE-2024-46821 depends largely on their use of Linux systems with AMD graphics hardware, particularly those running affected kernel versions. If exploited, this vulnerability could allow attackers to cause denial of service through kernel crashes or potentially escalate privileges, compromising system confidentiality and integrity. This is particularly critical for organizations relying on Linux servers or workstations for sensitive operations, including government agencies, financial institutions, and critical infrastructure providers. The vulnerability could disrupt services or enable further attacks if combined with other exploits. Since the vulnerability is in the kernel, successful exploitation could affect all processes running on the system, increasing the risk of widespread impact within affected environments.

European organizations should prioritize updating their Linux kernels to versions that include the patch for CVE-2024-46821 as soon as possible. Since the vulnerability is in the AMD DRM power management code, organizations using AMD GPUs on Linux should verify their kernel versions and apply vendor-supplied updates or mainline Linux kernel patches. System administrators should audit their environments to identify affected systems using tools that can report kernel versions and hardware configurations. Additionally, organizations should implement strict access controls to limit who can execute code or commands that might trigger this vulnerability, as exploitation likely requires local access. Monitoring kernel logs for unusual behavior or crashes related to the DRM subsystem can help detect attempted exploitation. Employing kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR) and enabling security modules like SELinux or AppArmor can further reduce exploitation risk. Finally, maintaining robust backup and recovery procedures will help mitigate the impact of any successful attacks.