CVE-2022-49890 is a vulnerability identified in the Linux kernel related to the handling of extended attributes (xattr) in the capabilities subsystem. Specifically, the issue arises in the function cap_inode_getsecurity(), which uses vfs_getxattr_alloc() to allocate memory for a temporary buffer (tmpbuf) intended to hold extended attribute data. The vulnerability is a potential memory leak occurring on an error path: after successfully allocating memory for tmpbuf, if the subsequent call to handler->get() fails, the allocated memory is not properly freed, leading to a leak. The problematic sequence involves allocation via vfs_getxattr_alloc(), reallocation with krealloc(), and then an error during handler->get(), after which the pointer to the allocated memory is overwritten without freeing the original allocation. This flaw could cause the kernel to consume increasing amounts of memory over time if the error path is triggered repeatedly. The patch involves ensuring that tmpbuf is freed if vfs_getxattr_alloc() fails, thus preventing the memory leak. The vulnerability affects certain Linux kernel versions identified by the commit hash 8db6c34f1dbc8e06aa016a9b829b06902c3e1340. There are no known exploits in the wild at this time, and no CVSS score has been assigned. The issue is primarily a resource management flaw rather than a direct code execution or privilege escalation vulnerability.

For European organizations, the impact of CVE-2022-49890 is primarily related to system stability and resource availability rather than direct compromise of confidentiality or integrity. Systems running affected Linux kernel versions may experience gradual memory exhaustion if the error path triggering the memory leak is exercised frequently, potentially leading to degraded performance or denial of service due to resource depletion. This could affect servers, embedded devices, or infrastructure components relying on Linux kernels with the vulnerable code. Organizations with critical infrastructure or high-availability systems could see service interruptions or increased maintenance overhead. While the vulnerability does not directly enable remote code execution or privilege escalation, the resulting instability could be exploited indirectly by attackers to cause denial of service conditions. European organizations with extensive Linux deployments, especially those running custom or older kernel versions without timely patching, are at risk of encountering these operational impacts.

To mitigate CVE-2022-49890, European organizations should prioritize updating their Linux kernel to the latest patched versions where this memory leak has been fixed. Kernel updates should be tested and deployed promptly in production environments. Additionally, organizations should implement monitoring of system memory usage and kernel logs to detect abnormal memory consumption patterns that could indicate exploitation of this leak. Employing automated patch management systems can help ensure timely application of kernel patches. For environments where immediate kernel upgrades are not feasible, consider restricting or auditing the use of extended attributes and capabilities features that invoke the vulnerable code paths. System administrators should also review custom kernel modules or third-party software that interacts with extended attributes to ensure they handle errors gracefully and do not exacerbate the leak. Finally, maintaining robust incident response plans to address potential denial of service scenarios will help minimize operational disruption.