CVE-2022-49191 is a vulnerability identified in the Linux kernel, specifically related to the mxser driver, which handles serial communication devices. The issue arises in the activate() function of the driver when the Line Status Register (LSR) equals 0xff, an unusual condition. Under this circumstance, the function returns an error without calling the shutdown() function. Because shutdown() is responsible for freeing the transmit buffer (xmit_buf), this omission leads to a memory leak where the buffer is not properly released. The vulnerability was addressed by modifying the code to ensure that the buffer is freed at a designated label, which is now jumped to both when LSR is 0xff and when the info->type is not set. This fix prevents the memory leak by guaranteeing proper resource cleanup even in error conditions. The vulnerability does not have an assigned CVSS score, and there are no known exploits in the wild at the time of publication. The affected versions are identified by a specific commit hash, indicating the issue is in certain kernel builds prior to the fix. The vulnerability is primarily a resource management flaw that could lead to increased memory consumption and potential denial of service if exploited repeatedly or under specific workloads.

For European organizations, the impact of CVE-2022-49191 is primarily related to system stability and availability. Since the vulnerability causes a memory leak in the Linux kernel's mxser driver, systems using affected kernel versions with this driver could experience degraded performance or eventual system crashes due to resource exhaustion. This is particularly relevant for organizations relying on Linux servers or embedded systems that utilize serial communication interfaces managed by the mxser driver. While the vulnerability does not directly expose confidentiality or integrity risks, the resulting denial of service could disrupt critical services, especially in industrial, telecommunications, or infrastructure environments where serial devices are common. European organizations in sectors such as manufacturing, energy, transportation, and telecommunications may be more susceptible due to their reliance on specialized hardware interfacing with Linux systems. However, the absence of known exploits and the requirement for specific kernel versions limit the immediate widespread impact. Nonetheless, unpatched systems could be vulnerable to targeted attacks or accidental resource depletion leading to operational disruptions.

To mitigate CVE-2022-49191, European organizations should prioritize updating their Linux kernel to the latest stable version that includes the patch fixing the mxser driver memory leak. Specifically, kernel maintainers and system administrators should verify that their kernel source includes the fix that properly frees the transmit buffer in all error paths within the activate() function. For environments where immediate patching is not feasible, monitoring system memory usage and logs related to serial device drivers can help detect abnormal behavior indicative of the leak. Additionally, organizations should audit the usage of the mxser driver to determine if it is actively used; if not, disabling or blacklisting the driver can reduce exposure. For embedded or specialized systems, coordination with hardware vendors to obtain updated firmware or kernel builds is essential. Implementing resource limits and watchdog timers may also help mitigate the impact of potential memory leaks by restarting affected services or systems before critical failures occur. Finally, maintaining a robust patch management process and vulnerability scanning tailored to Linux kernel components will ensure timely detection and remediation of similar issues.