---
id: CVE-2026-98581
title: 'nfc: llcp: Fix list corruption / refcount desync in nfc_llcp_recv_dm()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfc: llcp: Fix list corruption / refcount desync in nfc_llcp_recv_dm()

  nfc_llcp_recv_dm() handles DM(NOBOUND)/DM(REJ) for a socket that is still
  linked on local->conne…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f <
    dd2d24add86b3b63cd87cf2feff98ae119ba19a6
  - >-
    Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f <
    812731dd8511f5768f4ff279b3c18d85cd21da4b
  - >-
    Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f <
    dba1d9c7134afcb4b1bfad8c1b1b3f0ab5189b08
  - >-
    Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f <
    c1e9ed52a6697354366dddf190fbacee8ed2f7c5
  - >-
    Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f <
    7fb2c0eeb79bfad64065f539a453138abd0edda6
  - >-
    Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f <
    b94cf09720543cc34256c7aa88f8059cbe7c0419
  - >-
    Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f <
    320a2ff49bdce3f9a437b9a9ff341ff27d3bdbf1
  - >-
    Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f <
    bf1460acdf8cf5a07c819f59785d40f20d113099
  - Linux 3.6
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:18:54.696Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98581'
references:
  - url: 'https://git.kernel.org/stable/c/dd2d24add86b3b63cd87cf2feff98ae119ba19a6'
  - url: 'https://git.kernel.org/stable/c/812731dd8511f5768f4ff279b3c18d85cd21da4b'
  - url: 'https://git.kernel.org/stable/c/dba1d9c7134afcb4b1bfad8c1b1b3f0ab5189b08'
  - url: 'https://git.kernel.org/stable/c/c1e9ed52a6697354366dddf190fbacee8ed2f7c5'
  - url: 'https://git.kernel.org/stable/c/7fb2c0eeb79bfad64065f539a453138abd0edda6'
  - url: 'https://git.kernel.org/stable/c/b94cf09720543cc34256c7aa88f8059cbe7c0419'
  - url: 'https://git.kernel.org/stable/c/320a2ff49bdce3f9a437b9a9ff341ff27d3bdbf1'
  - url: 'https://git.kernel.org/stable/c/bf1460acdf8cf5a07c819f59785d40f20d113099'
tags:
  - cve.org
ingestedAt: '2026-10-18T15:45:12.253Z'
---

## Overview

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

nfc: llcp: Fix list corruption / refcount desync in nfc_llcp_recv_dm()

nfc_llcp_recv_dm() handles DM(NOBOUND)/DM(REJ) for a socket that is still
linked on local->connecting_sockets: it looks the socket up with
nfc_llcp_connecting_sock_get(), sets sk->sk_state = LLCP_CLOSED and
returns, without taking the socket lock and without unlinking the socket
from the connecting_sockets list.

llcp_sock_release() selects the list to unlink from by sk_state: a socket
in LLCP_CONNECTING is unlinked from connecting_sockets, otherwise from the
sockets list.  Because recv_dm left the socket physically on
connecting_sockets but in the LLCP_CLOSED state, release() takes the else
branch and calls nfc_llcp_sock_unlink(&local->sockets, sk).  That runs
sk_del_node_init() while holding sockets.lock, i.e. it removes the socket
from the connecting_sockets hlist under the wrong lock.  A concurrent
connect() linking another socket onto connecting_sockets under
connecting_sockets.lock then mutates the same hlist unserialized, which
corrupts the list and desyncs the sk_add_node()/sk_del_node_init()
sock_hold()/__sock_put() pairing.  An unprivileged local process holding
LLCP sockets, with the DM supplied by the remote peer over an established
LLCP link, can drive this to leak kernel sockets without bound (the
mis-decrement goes through the non-freeing __sock_put() path, so the
object is never released), leading to memory exhaustion / DoS.

This is the same class of bug that was fixed in the sibling handler
nfc_llcp_recv_cc() by commit b493ea2765cc ("nfc: llcp: Fix use-after-free
race in nfc_llcp_recv_cc()"); recv_dm did not receive the equivalent fix.

Fix it the same way: take lock_sock(), re-check that the socket is still
hashed (release() may have won the race), and for the NOBOUND/REJ case
unlink it from connecting_sockets before moving it to LLCP_CLOSED.  The
unlink drops the connecting_sockets membership reference via
sk_del_node_init(), leaving the socket unhashed, so the later
nfc_llcp_sock_unlink() in llcp_sock_release() becomes a no-op and no
double put occurs.

## Affected

- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < dd2d24add86b3b63cd87cf2feff98ae119ba19a6`
- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < 812731dd8511f5768f4ff279b3c18d85cd21da4b`
- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < dba1d9c7134afcb4b1bfad8c1b1b3f0ab5189b08`
- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < c1e9ed52a6697354366dddf190fbacee8ed2f7c5`
- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < 7fb2c0eeb79bfad64065f539a453138abd0edda6`
- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < b94cf09720543cc34256c7aa88f8059cbe7c0419`
- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < 320a2ff49bdce3f9a437b9a9ff341ff27d3bdbf1`
- `Linux >= a69f32af86e389dd232b1bb2269e202c1bfcc60f < bf1460acdf8cf5a07c819f59785d40f20d113099`
- `Linux 3.6`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.