# CVE-2026-90321: ocfs2: validate inline xattrs during inode block validation

> A use-after-free vulnerability in the Linux kernel's OCFS2 filesystem allows attackers to cause denial of service or execute code via corrupted inline xattr metadata.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-102530, BELL-CVE-2026-90321, DEBIAN-CVE-2026-90321, GHSA-wp5h-rffw-rh8w, UBUNTU-CVE-2026-90321

## What is CVE-2026-90321?

CVE-2026-90321 is a high-severity use after free vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

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

ocfs2: validate inline xattrs during inode block validation

Patch series "ocfs2: validate xattr entry bounds", v7.

This series validates OCFS2 xattr entry name/value bounds when xattr
metadata is read and validated, before getxattr() or listxattr() can walk
out-of-range entry arrays or offsets from corrupted metadata.

This patch (of 2):

ocfs2_validate_inode_block() verifies a dinode before OCFS2 users walk
metadata from it, but inline xattr metadata is still checked only in
operation-specific consumers.  The existing ibody lookup helper validates
inline header placement and entry count, but inode block validation does
not reject entry name/value bounds.

Add a flat xattr entry validator and call it from inode block validation
for inline xattrs.  Keep the operation paths on their existing
header/count lookup checks; the full entry bounds check now runs when the
inode block is validated at read time.

Reject corrupted inline xattr metadata before ocfs2_xattr_ibody_get() or
listxattr() can walk past the inline storage.

Validation reproduced this kernel report:
BUG: KASAN: use-after-free in ocfs2_xattr_find_entry+0x5a/0x170
Read of size 2 at addr ffff8881242a2000 by task python3/529
Call Trace:
  dump_stack_lvl+0x66/0xa0
  print_report+0xce/0x630
  kasan_report+0xe0/0x110
  ocfs2_xattr_find_entry+0x5a/0x170
  ocfs2_xattr_get_nolock+0x20a/0x820
  ocfs2_xattr_get+0x10c/0x1e0
  __vfs_getxattr+0xe2/0x130
  vfs_getxattr+0x185/0x1b0

## Which versions are affected by CVE-2026-90321?


## How do I fix CVE-2026-90321?

Apply the vendor's patch.

## Is CVE-2026-90321 being exploited?

There is no known exploitation of CVE-2026-90321 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90321 and fix it if it is affected.

What it is: CVE-2026-90321 is a high-severity use after free vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-90321 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-2026-90321/ (Markdown: https://insights.sbomify.com/CVE-2026-90321/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90321
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90321
- OSV: https://osv.dev/vulnerability/CVE-2026-90321

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90321/
Summaries are generated and may contain mistakes; the official description above is the record.