# CVE-2026-68312: cifs: fix cifsFileInfo leak on kmalloc failure in deferred close drain paths

> A memory leak in the Linux kernel CIFS module can lead to resource exhaustion and denial of service under memory pressure.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-94953, BELL-CVE-2026-68312, DEBIAN-CVE-2026-68312, GHSA-cm4r-jfcj-c3ff, UBUNTU-CVE-2026-68312

## What is CVE-2026-68312?

CVE-2026-68312 is a denial of service vulnerability in Linux, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

cifs: fix cifsFileInfo leak on kmalloc failure in deferred close drain paths

In cifs_close_deferred_file(), cifs_close_all_deferred_files(), and
cifs_close_deferred_file_under_dentry(), when a pending deferred close
is cancelled via cancel_delayed_work(), the subsequent kmalloc_obj() to
add the file to the local processing list may fail under memory pressure.
The loop breaks immediately, but the cancelled work is no longer pending
(it would have called _cifsFileInfo_put()), and the cfile is never added
to file_head for processing.  The cifsFileInfo reference and the open
server handle both leak.

Fix by saving the cfile that failed allocation in a local variable,
breaking as before, and calling _cifsFileInfo_put() on it after
releasing the lock.  Any files later in the iteration are unaffected
since their deferred work is still pending and will fire normally.

## Which versions are affected by CVE-2026-68312?


## How do I fix CVE-2026-68312?

Apply the vendor's patch.

## Is CVE-2026-68312 being exploited?

There is no known exploitation of CVE-2026-68312 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68312 and fix it if it is affected.

What it is: CVE-2026-68312 is a denial of service vulnerability in Linux, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-68312 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-68312/ (Markdown: https://insights.sbomify.com/CVE-2026-68312/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68312
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68312
- OSV: https://osv.dev/vulnerability/CVE-2026-68312

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68312/
Summaries are generated and may contain mistakes; the official description above is the record.