CVE-2022-49074 is a vulnerability identified in the Linux kernel specifically within the irqchip/gic-v3 subsystem, which handles the Generic Interrupt Controller (GIC) version 3. The issue arises from an incorrect polling mechanism for the RWP (Register Write Pending) bit in the redistributors (RDs) of the GIC. The vulnerability stems from the fact that the code erroneously checks the bit index used for the distributor component rather than the correct bit index for the redistributors. This misalignment means that the kernel may incorrectly assume that a write operation to the redistributor registers has completed when it has not, potentially leading to race conditions or inconsistent states within the interrupt controller. The flaw was present for approximately eight years before being discovered and fixed. Although the description does not explicitly state the direct exploitation method or impact, the nature of the bug suggests it could cause system instability, incorrect interrupt handling, or denial of service due to improper synchronization of hardware register writes. The vulnerability affects multiple versions of the Linux kernel identified by the same commit hash, indicating a long-standing issue in the codebase. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The fix involves correcting the polling logic to check the appropriate bit index for the redistributors, ensuring proper synchronization and preventing potential race conditions or system faults related to interrupt handling.

For European organizations, the impact of CVE-2022-49074 could be significant, especially for those relying on Linux-based systems in critical infrastructure, telecommunications, cloud services, and embedded systems that utilize ARM architecture with GICv3 interrupt controllers. Improper handling of interrupt controller registers can lead to system instability, unexpected reboots, or denial of service conditions, which could disrupt business operations and critical services. Organizations running Linux kernels with the affected versions may experience degraded system reliability or security risks if attackers find ways to exploit this flaw to cause kernel crashes or escalate privileges via hardware interrupt manipulation. Although no active exploits are known, the long presence of the bug increases the risk that sophisticated attackers or nation-state actors could develop targeted exploits. This is particularly relevant for sectors such as finance, healthcare, and government agencies in Europe, where uptime and system integrity are paramount. Additionally, embedded devices and IoT systems using affected Linux kernels could be vulnerable, potentially impacting supply chains and industrial control systems. The lack of a CVSS score and known exploits means the threat is currently theoretical but should be treated with caution given the kernel-level nature of the vulnerability.

European organizations should prioritize updating their Linux kernel versions to the patched releases that correct the RWP polling logic in the irqchip/gic-v3 subsystem. Since this is a kernel-level vulnerability, applying vendor-supplied kernel patches or upgrading to the latest stable kernel versions is the most effective mitigation. For embedded and IoT devices, coordinate with hardware and software vendors to ensure firmware and kernel updates are applied promptly. Additionally, organizations should audit their systems to identify those running affected kernel versions, especially on ARM-based platforms using GICv3. Implementing strict access controls and monitoring for unusual kernel or hardware interrupt behavior can help detect potential exploitation attempts. Where possible, employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR) and secure boot to reduce the risk of exploitation. Finally, maintain robust incident response plans to quickly address any instability or suspicious activity related to kernel faults.