CVE-2021-47609 is a vulnerability identified in the Linux kernel, specifically within the ARM SCPI (System Control and Power Interface) generic power domain (genpd) driver. The issue arises from a lack of proper boundary checks when copying the SCPI device name from the device tree node into the scpi_pd->name buffer. The name string is set with a maximum size of 30 characters, but without bounds checking, a longer string can cause a buffer overflow. This overflow occurs because the code attempts to copy the device name directly into a fixed-size buffer without verifying the length, leading to potential memory corruption. The vulnerability has been addressed by modifying the code to use devm_kasprintf, which dynamically allocates the string buffer, thereby preventing overflow by ensuring the buffer size matches the string length. This fix eliminates the risk of buffer overflow by avoiding static buffer allocation and instead using dynamic memory management for the device name string. Although no known exploits are currently reported in the wild, the vulnerability could theoretically be exploited by an attacker with the ability to influence device tree data or device naming in the kernel environment, potentially leading to arbitrary code execution or kernel crashes due to memory corruption. The vulnerability affects Linux kernel versions identified by the commit hash 8bec4337ad4023b26de35d3b0c3a3b2735ffc5c7 and similar builds that have not applied the patch. Since the vulnerability is in the kernel, it impacts all systems running affected Linux versions on ARM architectures utilizing the SCPI genpd driver, which is common in embedded and ARM-based devices.

For European organizations, the impact of CVE-2021-47609 depends largely on their use of ARM-based Linux systems, particularly those employing the SCPI genpd driver. This includes embedded systems, IoT devices, and ARM servers or workstations. Exploitation could lead to kernel-level memory corruption, causing system instability, crashes, or potentially privilege escalation if an attacker can execute arbitrary code in kernel space. This could compromise the confidentiality, integrity, and availability of affected systems. Critical infrastructure sectors such as telecommunications, manufacturing, automotive, and energy that deploy ARM-based Linux devices could face operational disruptions or data breaches if exploited. The absence of known exploits reduces immediate risk, but the vulnerability's presence in the kernel layer means that successful exploitation could have severe consequences. European organizations relying on ARM Linux platforms should consider this vulnerability a significant risk, especially in environments where device tree data can be influenced or where untrusted code execution is possible.

To mitigate CVE-2021-47609, organizations should: 1) Apply the official Linux kernel patch that replaces static buffer allocation with dynamic allocation using devm_kasprintf to prevent buffer overflow. 2) Update all ARM-based Linux systems to the latest kernel versions containing this fix. 3) Audit device tree configurations and restrict modifications to trusted administrators to prevent malicious manipulation of device names. 4) Implement strict access controls and monitoring on systems that allow device tree updates or kernel module loading. 5) Employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR) and Kernel Page Table Isolation (KPTI) to reduce exploitation impact. 6) Use runtime security tools like SELinux or AppArmor to limit kernel module behaviors. 7) Conduct thorough testing after patching to ensure system stability and verify that the vulnerability is resolved. These steps go beyond generic patching by emphasizing configuration management, access control, and kernel security best practices tailored to the nature of this vulnerability.