CVE-2025-23158 is a vulnerability identified in the Linux kernel's media subsystem, specifically within the Venus hardware interface (hfi) driver responsible for communication between the Linux driver and video firmware. The vulnerability arises due to improper validation of the queue size (qsize) used for shared memory communication between the driver and the video firmware. The firmware can maliciously or erroneously modify the qsize to an invalidly large value. This leads to a miscalculation of the available empty space in the queue buffer, as the empty_space variable is computed based on the qsize without verifying its correctness. Consequently, the new write index (new_wr_idx) is not properly checked against the actual allocated buffer size, resulting in an out-of-bounds (OOB) write when the driver attempts to copy data (via memcpy) into the queue. This OOB write can corrupt adjacent memory, potentially leading to kernel memory corruption, system instability, or privilege escalation. The patch for this vulnerability involves adding proper validation checks to ensure that qsize remains within the allocated buffer size before any read or write operations are performed on the queue. The vulnerability affects multiple versions of the Linux kernel identified by the commit hash d96d3f30c0f2f564f6922bf4ccdf4464992e31fb, and was published on May 1, 2025. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet.

For European organizations, this vulnerability poses a significant risk especially for those relying on Linux-based systems with media processing capabilities, such as video streaming services, telecommunications infrastructure, multimedia production environments, and embedded systems using the Venus hardware interface. Exploitation could allow attackers to execute arbitrary code with kernel privileges, leading to full system compromise, data breaches, or denial of service. This is particularly critical for sectors handling sensitive data or critical infrastructure, including finance, healthcare, government, and industrial control systems. Given the widespread use of Linux in servers, cloud environments, and IoT devices across Europe, the vulnerability could be leveraged to disrupt services or gain unauthorized access. Although no exploits are currently known, the complexity of the vulnerability and its kernel-level impact make it a high-risk issue that requires prompt attention to prevent potential future exploitation.

European organizations should immediately audit their Linux kernel versions to identify if they are running affected versions containing the vulnerable Venus hfi driver code. Applying the official Linux kernel patches that add validation checks for qsize is the primary mitigation step. If patching is not immediately feasible, organizations should consider disabling or restricting access to the Venus media interface where possible, especially in multi-tenant or exposed environments. Employing kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), Kernel Page Table Isolation (KPTI), and enabling security modules like SELinux or AppArmor can reduce exploitation risk. Continuous monitoring for unusual kernel memory activity and implementing strict access controls to firmware interfaces are also recommended. Finally, organizations should stay updated with vendor advisories and security bulletins for any emerging exploit reports or additional patches.