CVE-2022-49859 is a vulnerability identified in the Linux kernel affecting the lapbether network driver, specifically within the lapbeth_open() function. The root cause stems from improper handling when lapb_register() fails during the initial activation of the lapb device. In this failure scenario, the NAPI (New API for network packet processing) is not properly disabled. Consequently, when the lapb device is brought up a second time, an invalid opcode exception occurs, leading to a kernel BUG and system crash. The vulnerability manifests as an invalid opcode error triggered by napi_enable() being called on an improperly initialized or partially registered device. The stack trace indicates the failure occurs deep within the network core device management code, ultimately causing a kernel panic. This issue can lead to denial of service (DoS) conditions due to kernel crashes when the affected network device is cycled or reinitialized. The vulnerability affects Linux kernel versions containing the specified commit hash 514e1150da9cd8d7978d990a353636cf1a7a87c2, and it has been publicly disclosed without an assigned CVSS score or known exploits in the wild. The lapb (Link Access Procedure, Balanced) protocol is used in some telecommunications and networking environments, so systems utilizing this protocol stack or related network drivers are at risk. The vulnerability requires local administrative privileges to trigger since it involves device state changes and ioctl system calls, but no user interaction is needed beyond that. The issue has been patched in the Linux kernel, although no direct patch links are provided in the source data.

For European organizations, the primary impact of CVE-2022-49859 is the potential for denial of service on Linux systems running affected kernel versions with lapb network drivers enabled. This could disrupt critical network services, especially in telecom, industrial control, or specialized networking environments that rely on the lapb protocol. Systems experiencing kernel panics may require reboots, leading to downtime and potential loss of availability for network-dependent applications. While the vulnerability does not appear to allow privilege escalation or remote code execution, the resulting instability could be exploited to degrade service reliability. Organizations operating Linux-based infrastructure in sectors such as telecommunications, manufacturing, or research institutions using specialized network stacks may be particularly vulnerable. The lack of known exploits in the wild reduces immediate risk, but unpatched systems remain susceptible to accidental or intentional triggering of the bug. Given the kernel-level nature of the flaw, recovery from crashes may require manual intervention, impacting operational continuity.

European organizations should prioritize updating Linux kernels to versions where this vulnerability is patched. Since the vulnerability arises from lapb device initialization failures, administrators should audit their systems to identify usage of lapb or lapbether network drivers and assess whether these are active or required. If lapb functionality is not needed, disabling or blacklisting the lapb module can reduce exposure. For systems requiring lapb, ensure kernel updates are applied promptly from trusted sources. Additionally, implementing kernel crash monitoring and automated recovery mechanisms can minimize downtime caused by unexpected panics. Network device initialization scripts and error handling should be reviewed to prevent repeated failed attempts that could trigger the bug. Organizations should also restrict local administrative access to trusted personnel to reduce the risk of intentional exploitation. Finally, maintaining comprehensive system backups and recovery plans will aid in rapid restoration if crashes occur.