---
id: "CVE-2026-99010"
kind: "vulnerability"
aliases: ["CVE-2026-99010"]
title: "Linux kernel: Bluetooth RFCOMM leaks a packet buffer per frame after socket close"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["bluetooth", "kernel", "linux", "runtime", "self-hosted"]
not_affected_if: ["no-bluetooth", "rfcomm-module-not-loaded"]
published_at: "2026-10-23T13:17:23+00:00"
first_seen_at: "2026-10-23T21:57:33+00:00"
updated_at: "2026-10-25T04:55:49+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99010", "first_seen_at": "2026-10-23T21:57:33+00:00"}]
---

# Linux kernel: Bluetooth RFCOMM leaks a packet buffer per frame after socket close

When a Bluetooth RFCOMM connection has no owning socket, incoming data frames are handed to a callback that never frees them, so the kernel leaks memory on every frame. A nearby remote device that keeps sending data can keep growing that leak until the kernel runs out of memory.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `uname -r` and compare against the fixed kernel builds listed by your distribution.
- Check whether Bluetooth RFCOMM is in use with `lsmod | grep rfcomm`; if the module is not loaded, the code path is not reachable.

## Fix

- Update the Linux kernel to a build that includes the upstream commit freeing the skb when the DLC has no owner; the sources do not list fixed version numbers, so unknown.
- Until patched, unload the RFCOMM module with `modprobe -r rfcomm` on hosts that do not need Bluetooth serial.

## Timeline

- 2026-10-23T21:57:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99010

## From the sources

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

Bluetooth: RFCOMM: free the skb when the DLC has no owner

rfcomm_recv_data() hands the skb to d->data_ready() and returns 0
without freeing it, so the callback owns the skb from that point on.
The tty implementation frees it when the DLC has been detached from its
device:

  static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc,
                                    struct sk_buff *skb)
  {
          struct rfcomm_dev *dev = dlc->owner;

          if (!dev) {
                  kfree_skb(skb);
                  return;
          }

The socket implementation returns without freeing it, and the skb is
leaked.

A connected DLC can have no owner: rfcomm_sock_destruct() clears
d->owner, while the DLC itself stays on the session until it is closed.
Data frames that arrive in that window still find d->state ==
BT_CONNECTED in rfcomm_recv_data() and are handed to the callback, one
leaked skb each.

The leak does not stop on its own either.  The remote runs out of
credits only once RFCOMM_RX_THROTTLED is set, and for a socket the only
place that sets it is rfcomm_sk_data_ready() itself, below the return.
rfcomm_process_dlcs() keeps granting credits, so the remote keeps
sending and the leak keeps growing.

Free the skb, as the tty side does.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_