CVE-2025-38187: 
Linux Kernel vulnerability analysis and mitigation

CVE-2025-38187 is a vulnerability discovered in the Linux kernel, specifically in the drm/nouveau driver component. The vulnerability was disclosed on July 4, 2025, and affects the RPC (Remote Procedure Call) handling mechanism in the r535gsprpc_push() function (NVD, RedHat).

The vulnerability is a use-after-free issue that occurs when the RPC container is released after being passed to r535gsprpc_send(). When sending the initial fragment of a large RPC and passing the caller's RPC container, the container is freed prematurely. This premature freeing leads to subsequent attempts to send remaining fragments resulting in a use-after-free condition. The vulnerability has been assigned a CVSS v3.1 base score of 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) (RedHat).

The vulnerability primarily affects the availability of the system. According to the CVSS metrics, while there is no impact on confidentiality or integrity, there is a high impact on system availability. The local nature of the vulnerability means it requires local access to exploit (RedHat).

The vulnerability has been resolved by allocating a temporary RPC container for holding the initial fragment of a large RPC when sending, and freeing the caller's container only when all fragments are successfully sent. This fix has been implemented in the Linux kernel (NVD).