CVE-2025-22069 is a vulnerability identified in the Linux kernel specifically affecting the RISC-V architecture implementation of the ftrace subsystem. The issue arises from a mismatch in the stack layout used to construct arguments for the function ftrace_return_to_handler within the return_to_handler routine. This mismatch causes the stack frame pointer to be incorrect, leading to kernel warnings such as "Bad frame pointer" and potentially unstable kernel behavior. The vulnerability was discovered when running the Linux Test Project (LTP) trace ftrace_stress_test.sh on RISC-V, which triggered kernel warnings indicating corrupted stack frames. The root cause is that the stack layout does not align with the __arch_ftrace_regs structure expected by the RISC-V architecture, causing unexpected results during function tracing. This flaw can lead to kernel instability or crashes when the ftrace subsystem is used, particularly when dynamic fprobes are enabled and tracing is active. The vulnerability affects Linux kernel versions containing the specified commit hashes and was publicly disclosed in April 2025. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, the impact of CVE-2025-22069 depends largely on their use of Linux systems running on RISC-V architecture, which is currently less common than x86 or ARM architectures but is gaining traction in embedded systems, IoT devices, and specialized computing environments. If exploited or triggered unintentionally, this vulnerability could cause kernel panics or instability, leading to denial of service conditions on affected systems. This could disrupt critical services, particularly in sectors relying on embedded Linux devices such as telecommunications, industrial control systems, and research institutions experimenting with RISC-V hardware. Although no direct remote exploitation vector is described, the vulnerability could be triggered locally by users or processes with the ability to enable ftrace probes, potentially allowing for privilege escalation or system disruption. The lack of a known exploit reduces immediate risk, but the kernel instability could still affect system reliability and availability, impacting operational continuity and potentially leading to data loss or service outages in sensitive environments.

European organizations should prioritize updating their Linux kernels to versions where this vulnerability is patched, especially if they operate RISC-V based systems. Since the issue relates to the ftrace subsystem, administrators should consider disabling dynamic fprobes or tracing features on RISC-V systems if kernel updates cannot be immediately applied. Additionally, restricting access to the /sys/kernel/debug/tracing interface to trusted users only can reduce the risk of local exploitation. Organizations should audit their use of RISC-V Linux systems and evaluate whether ftrace functionality is necessary for their operations. Implementing kernel hardening measures and monitoring kernel logs for unusual ftrace warnings can help detect attempts to trigger this vulnerability. For embedded or IoT devices, firmware updates incorporating the patched kernel should be deployed promptly. Finally, maintaining a robust incident response plan to address potential kernel crashes or denial of service events will help mitigate operational impacts.