CVE-2025-22028 is a vulnerability identified in the Linux kernel specifically related to the media subsystem, more precisely the vimc (Virtual Media Controller) driver. The issue arises from improper handling of the .s_stream() operation for subdevices (subdevs) that are either unstarted or stopped. The vulnerability was reported by Syzbot, an automated kernel fuzzing system, which detected a warning triggered by the call_s_stream() function. This function checks whether the .s_stream() operation should be invoked on subdevs, but prior to the fix, it did not properly skip this call for entities that had not been started or were already stopped. This could lead to unexpected behavior or kernel warnings, potentially causing instability or denial of service in the media subsystem. The root cause was that the vimc_streamer_pipeline_terminate() function did not ensure that .s_stream() was only called on entities that had been properly started. The fix involved adding a check to skip the .s_stream() call unless the entity was previously started, thus preventing the warning and potential misuse of the streaming operation on invalid states. This vulnerability affects specific Linux kernel versions identified by their commit hashes, including versions around 6.13.0-rc2. The issue is located in the media drivers, particularly those related to video4linux2 (v4l2) and the vimc test drivers. The vulnerability does not have a CVSS score assigned yet and there are no known exploits in the wild as of the published date. Because the vulnerability is in a kernel driver related to media streaming, exploitation would likely require local access and interaction with the media subsystem, possibly through ioctl calls to the video device interfaces. The impact is primarily on system stability and reliability rather than direct privilege escalation or data leakage, but improper handling of kernel operations can sometimes be leveraged in complex attack chains.

For European organizations, the impact of CVE-2025-22028 depends largely on the deployment of Linux systems utilizing the affected kernel versions and specifically the vimc media driver. Organizations using Linux servers or workstations for media processing, video streaming, or development environments that include the vimc driver could experience kernel warnings or crashes leading to denial of service conditions. This could disrupt services relying on media capture or streaming, such as video conferencing, surveillance systems, or multimedia processing pipelines. While the vulnerability does not appear to directly enable privilege escalation or remote code execution, the instability caused by improper kernel operations can degrade system availability and reliability. In critical infrastructure or industrial environments where Linux-based media devices are used, this could impact operational continuity. Additionally, organizations with development or testing environments using the vimc driver might face increased debugging and maintenance overhead. Given the lack of known exploits and the requirement for local interaction with the media subsystem, the threat is more relevant to organizations with direct access to affected Linux systems rather than remote attackers. However, insider threats or compromised local users could potentially trigger the vulnerability to cause denial of service.

1. Update the Linux kernel to a version that includes the fix for CVE-2025-22028. Monitor kernel release notes and apply patches promptly, especially if using kernel versions around 6.13.0-rc2 or those identified by the affected commit hashes. 2. For systems where immediate kernel updates are not feasible, consider disabling or unloading the vimc media driver if it is not required, to eliminate the attack surface. 3. Restrict access to media device interfaces (e.g., /dev/video*) using strict permissions and access control mechanisms to prevent unauthorized local users from interacting with the vulnerable driver. 4. Implement monitoring for kernel warnings and errors related to media subsystem operations to detect potential exploitation attempts or instability caused by this vulnerability. 5. In development and testing environments, ensure that fuzzing tools like Syzbot are used to proactively identify similar issues and validate kernel stability after updates. 6. Educate system administrators and security teams about the specific nature of this vulnerability to prioritize patching and access controls appropriately.