# CVE-2026-98580: nfc: llcp: Fix race condition in accept_queue lifecycle

> A race condition in the Linux kernel NFC LLCP subsystem allows concurrent socket release, leading to use-after-free or NULL dereference, potentially causing crashes or code execution.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-109194, BELL-CVE-2026-98580, DEBIAN-CVE-2026-98580, GHSA-f48w-jg7j-gjm2, UBUNTU-CVE-2026-98580

## What is CVE-2026-98580?

CVE-2026-98580 is a vulnerability in Linux, published on 18 Oct 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:

nfc: llcp: Fix race condition in accept_queue lifecycle

In nfc_llcp_socket_release(), sockets and listener accept queues are
walked under the local sockets rwlock and bh_lock_sock().  However,
bh_lock_sock() does not synchronise against process-context lock_sock()
held by nfc_llcp_accept_dequeue() during accept().  Because
socket_release() does not check sock_owned_by_user(), both paths can
concurrently unlink and release the same child socket, resulting in
use-after-free or a NULL pointer dereference of child->parent in
nfc_llcp_accept_unlink().

Fix this synchronisation race by having nfc_llcp_socket_release() use
process-context lock_sock() instead of bh_lock_sock():

1. Pop sockets from the local sockets list under the write lock using
   nfc_llcp_sock_list_pop() so lock_sock() can be acquired without
   holding the rwlock.

2. Because lock_sock() can sleep, defer the final release of the
   nfc_llcp_local structure to a workqueue (release_work).  This avoids
   a sleeping-in-atomic bug when the last local reference is dropped
   from softirq context.  Additionally, hold a single device reference
   on local from registration until final destruction.

3. In nfc_llcp_local_get(), use kref_get_unless_zero() to prevent
   resurrecting a local object whose teardown has been scheduled.

4. In llcp_sock_accept(), verify that the listener socket state is still
   LLCP_LISTEN after waking from schedule_timeout() to prevent hangs if
   the listener is closed concurrently.

5. When unlinking unaccepted child sockets during listener release,
   unlink them from local->sockets, call sock_orphan(), and drop their
   initial sk_alloc creation reference via sock_put().

6. Make nfc_llcp_accept_unlink() idempotent by guarding parent access with
   a NULL check.

## Which versions are affected by CVE-2026-98580?


## How do I fix CVE-2026-98580?

Apply the vendor's patch.

## Is CVE-2026-98580 being exploited?

There is no known exploitation of CVE-2026-98580 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98580 and fix it if it is affected.

What it is: CVE-2026-98580 is a vulnerability in Linux, published on 18 Oct 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-2026-98580 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-2026-98580/ (Markdown: https://insights.sbomify.com/CVE-2026-98580/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98580
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98580
- OSV: https://osv.dev/vulnerability/CVE-2026-98580

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98580/
Summaries are generated and may contain mistakes; the official description above is the record.