CVE-2025-23151 is a vulnerability identified in the Linux kernel specifically within the MHI (Modem Host Interface) bus host driver. The issue arises from a race condition between the functions mhi_unprepare_from_transfer() and mhi_queue_buf(). The mhi_unprepare_from_transfer() function is used by client drivers to quiesce or pause incoming data during the teardown process of the client driver. However, if the client driver is simultaneously processing data, it may call mhi_queue_buf(), which in turn invokes mhi_gen_tre(). The vulnerability occurs because mhi_gen_tre() does not verify the channel state after acquiring a lock. If mhi_gen_tre() executes after the channel has been torn down by mhi_unprepare_from_transfer(), it attempts to access deinitialized data, leading to an invalid dereference and a kernel panic due to a page fault. This can cause the affected system to crash unexpectedly. The fix involves modifying mhi_gen_tre() to confirm the channel state is valid before proceeding or returning an error to avoid accessing invalid memory. This vulnerability affects multiple versions of the Linux kernel as indicated by the affected commit hashes. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The vulnerability is categorized as a race condition leading to a denial of service (system crash) due to improper synchronization and state validation in the MHI host driver code.

For European organizations relying on Linux-based systems, especially those using hardware or embedded devices that utilize the MHI bus interface (commonly found in modem and communication subsystems), this vulnerability could lead to unexpected system crashes or denial of service conditions. This can disrupt critical services, particularly in telecommunications, industrial control systems, and embedded environments where Linux is prevalent. The kernel panic caused by this race condition could result in downtime, loss of availability, and potential cascading failures in dependent systems. While this vulnerability does not appear to allow privilege escalation or remote code execution, the availability impact alone can be significant for infrastructure providers, cloud services, and enterprises with Linux-based servers or network equipment. The lack of known exploits reduces immediate risk, but the vulnerability’s presence in the kernel means that any device running affected Linux versions is susceptible if the vulnerable MHI driver is in use. European organizations with embedded Linux devices in telecommunications or IoT sectors should be particularly vigilant.

1. Apply the official Linux kernel patches that address CVE-2025-23151 as soon as they become available from trusted sources or Linux distribution vendors. 2. Identify and inventory all systems running affected Linux kernel versions, focusing on those using MHI bus interfaces, such as modems or embedded communication devices. 3. For embedded or specialized devices, coordinate with hardware vendors to obtain updated firmware or kernel versions that include the fix. 4. Implement monitoring to detect kernel panics or unexpected reboots that may indicate exploitation or triggering of this race condition. 5. Where possible, isolate critical systems using MHI interfaces from untrusted networks to reduce the risk of accidental triggering. 6. Conduct thorough testing of updated kernels in staging environments to ensure stability and compatibility before deployment. 7. Educate system administrators and security teams about the nature of this vulnerability to ensure rapid response if symptoms appear. 8. Consider implementing kernel lockdown or integrity monitoring features to detect anomalous kernel behavior related to this vulnerability.