# CVE-2026-93252: ocfs2: fix circular locking dependency in ocfs2_init_acl()

> A local attacker can trigger a deadlock in the OCFS2 filesystem via circular locking, causing a denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-93252, DEBIAN-CVE-2026-93252, GHSA-358c-95r2-55gw, UBUNTU-CVE-2026-93252

## What is CVE-2026-93252?

CVE-2026-93252 is a vulnerability in Linux, published on 24 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

ocfs2: fix circular locking dependency in ocfs2_init_acl()

A lockdep warning indicates a circular locking dependency between
`&oi->ip_xattr_sem` and `&journal->j_trans_barrier`:

WARNING: possible circular locking dependency detected
is trying to acquire lock:
 (&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_init_acl+0x2fd/0x7e0
 fs/ocfs2/acl.c:367

but task is already holding lock:
 (&journal->j_trans_barrier){.+.+}-{4:4}, at: ocfs2_start_trans+0x3ab/0x700
 fs/ocfs2/journal.c:369

The deadlock involves two code paths: Path 1 (setxattr) where
`ocfs2_xattr_set()` acquires `ip_xattr_sem` (write) and then starts a
transaction, which acquires `j_trans_barrier` (read); and Path 2
(mkdir/mknod) where `ocfs2_mknod()` starts a transaction (`j_trans_barrier`
read) and then calls `ocfs2_init_acl()`, which attempts to acquire
`ip_xattr_sem` (read) on the parent directory to retrieve the default ACL.

Because rw_semaphores are subject to writer priority, a pending writer on
`j_trans_barrier` (e.g., the journal commit thread) can cause Path 1 to
block, while Path 2 is blocked waiting for Path 1 to release
`ip_xattr_sem`.

The patch fixes the lock ordering by precomputing the ACL state before
starting the OCFS2 transaction, while preserving POSIX ACL storage
semantics and the existing inode/security initialization order. By reading
the parent directory's default ACL and preparing the new inode's ACLs
outside the transaction, `ip_xattr_sem` is always acquired before
`j_trans_barrier`.

`struct ocfs2_acl_state` encapsulates the prepared ACL state, while
`ocfs2_acl_init_prepare()` and `ocfs2_acl_init_release()` avoid code
duplication between `ocfs2_mknod()` and `ocfs2_init_security_and_acl()`.
`ocfs2_calc_xattr_init()` and `ocfs2_init_acl()` use this precomputed
state, removing internal `ip_xattr_sem` acquisition and redundant disk
reads.

Additionally, remove the `ip_xattr_sem` acquisition from
`ocfs2_xattr_set_handle()`. This function is only used while initializing a
new inode that has not yet been inserted into the inode hash or attached to
a dentry, meaning there is no risk of concurrent access and the lock is
unnecessary.

## Which versions are affected by CVE-2026-93252?


## How do I fix CVE-2026-93252?

Apply the vendor's patch.

## Is CVE-2026-93252 being exploited?

There is no known exploitation of CVE-2026-93252 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93252 and fix it if it is affected.

What it is: CVE-2026-93252 is a vulnerability in Linux, published on 24 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-93252 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-2026-93252/ (Markdown: https://insights.sbomify.com/CVE-2026-93252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93252
- OSV: https://osv.dev/vulnerability/CVE-2026-93252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93252/
Summaries are generated and may contain mistakes; the official description above is the record.