CVE-2022-48660 is a medium-severity vulnerability identified in the Linux kernel's GPIO (General Purpose Input/Output) subsystem, specifically within the gpiolib character device (cdev) interface. The issue arises from improper handling of the lineevent_state::irq variable during IRQ (Interrupt Request) registration and cleanup on certain hardware platforms, notably the NXP LS1028 platform. When a GPIO test is run using the gpiomon tool with specific parameters (e.g., monitoring rising-edge events on gpiochip1 line 25), a warning trace is generated due to a race condition in the IRQ management logic. The root cause is that the lineevent_state::irq is set before the successful registration of the threaded IRQ via request_threaded_irq(). If the IRQ registration fails, the cleanup function lineevent_free() is called, which attempts to free the IRQ using free_irq(). Because lineevent_state::irq was already set, free_irq() is called on an invalid or unregistered IRQ, leading to a warning trace and potential instability. The fix involves setting lineevent_state::irq only after the IRQ registration succeeds, preventing the erroneous free_irq() call during cleanup. This vulnerability does not directly lead to confidentiality or integrity breaches but can cause denial of service (DoS) conditions by triggering kernel warnings and potentially destabilizing the system due to improper IRQ handling. The CVSS 3.1 score is 5.5 (medium), reflecting a local attack vector with low complexity, requiring low privileges and no user interaction, impacting availability only. No known exploits are reported in the wild at this time.

For European organizations, the impact of CVE-2022-48660 is primarily related to system stability and availability, especially for those running Linux on embedded or specialized hardware platforms such as the NXP LS1028. Industries relying on Linux-based IoT devices, industrial control systems, telecommunications infrastructure, or network appliances that utilize GPIO interfaces may experience service interruptions or degraded performance if this vulnerability is triggered. While it does not compromise data confidentiality or integrity, the potential for denial of service could disrupt critical operations, particularly in sectors like manufacturing, energy, transportation, and telecommunications. Organizations with strict uptime requirements or those operating critical infrastructure should be aware of this vulnerability to avoid unexpected kernel warnings or crashes that could lead to downtime or require system reboots. Since exploitation requires local access and low privileges, insider threats or compromised local accounts pose the most significant risk vectors.

To mitigate CVE-2022-48660, organizations should: 1) Apply the official Linux kernel patches that correct the IRQ registration logic by ensuring lineevent_state::irq is set only after successful IRQ registration. 2) For systems using the NXP LS1028 platform or similar hardware with GPIO event monitoring, update to the latest stable kernel versions that include this fix. 3) Implement strict access controls and monitoring on systems with local user accounts to prevent unauthorized local execution of GPIO tests or related operations that could trigger the vulnerability. 4) Employ kernel hardening techniques and runtime integrity monitoring to detect abnormal kernel warnings or traces indicative of IRQ mismanagement. 5) For embedded or industrial devices where kernel updates are challenging, consider isolating affected devices from critical networks or applying compensating controls such as limiting local user privileges and disabling unnecessary GPIO event monitoring tools. 6) Maintain robust incident response procedures to quickly address any system instability or crashes potentially related to this vulnerability.