---
id: CVE-2026-63871
title: 'Bluetooth: ISO: Fix data-race on iso_pi fields in hci_get_route calls'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: ISO: Fix data-race on iso_pi fields in hci_get_route calls

  iso_connect_bis(), iso_connect_cis(), iso_listen_bis(), and
  iso_conn_big_sync() call hci_get_rout…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= c524f9561c657b8af26dd4f67092b8928261aa62 <
    122b6a8b0c75b5f808aa6ea68e97103330b9ffa7
  - >-
    Linux >= 241f51931c35085449502c10f64fb3ecd6e02171 <
    9798f7d41d85ff763afd1f1cc0533b5c416c8348
  - >-
    Linux >= 241f51931c35085449502c10f64fb3ecd6e02171 <
    ab84fd7779a2a7ff5d2c8eac212c43733f56216e
  - >-
    Linux >= 241f51931c35085449502c10f64fb3ecd6e02171 <
    859bb1f4cb615d98c9c1ab2bd76ebb0b8fe46020
  - >-
    Linux >= 241f51931c35085449502c10f64fb3ecd6e02171 <
    9ca7053d6215d89c33f28893bfd1625a32919d3f
  - Linux >= 6.1.9 < 6.1.191
  - Linux 6.2
published: '2026-07-19'
updated: '2026-10-30'
sourceUpdated: '2026-10-30T12:27:20.291Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-63871'
references:
  - url: 'https://git.kernel.org/stable/c/122b6a8b0c75b5f808aa6ea68e97103330b9ffa7'
  - url: 'https://git.kernel.org/stable/c/9798f7d41d85ff763afd1f1cc0533b5c416c8348'
  - url: 'https://git.kernel.org/stable/c/ab84fd7779a2a7ff5d2c8eac212c43733f56216e'
  - url: 'https://git.kernel.org/stable/c/859bb1f4cb615d98c9c1ab2bd76ebb0b8fe46020'
  - url: 'https://git.kernel.org/stable/c/9ca7053d6215d89c33f28893bfd1625a32919d3f'
tags:
  - cve.org
epss: 0.00166
epssPercentile: 0.05832
ingestedAt: '2026-11-05T15:02:32.393Z'
---

## Overview

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

Bluetooth: ISO: Fix data-race on iso_pi fields in hci_get_route calls

iso_connect_bis(), iso_connect_cis(), iso_listen_bis(), and
iso_conn_big_sync() call hci_get_route() using iso_pi(sk)->dst,
iso_pi(sk)->src, and iso_pi(sk)->src_type without holding lock_sock().

These fields may be modified concurrently by connect() or setsockopt()
on the same socket, resulting in data-races reported by KCSAN.

Fix this by snapshotting the required fields under lock_sock() before
calling hci_get_route().

BUG: KCSAN: data-race in memcmp+0x45/0xb0

race at unknown origin, with read to 0xffff8880122135cf of 1 bytes
by task 333 on cpu 1:
 memcmp+0x45/0xb0
 hci_get_route+0x27e/0x490
 iso_connect_cis+0x4c/0xa10
 iso_sock_connect+0x60e/0xb30
 __sys_connect_file+0xbd/0xe0
 __sys_connect+0xe0/0x110
 __x64_sys_connect+0x40/0x50
 x64_sys_call+0xcad/0x1c60
 do_syscall_64+0x133/0x590
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

## Affected

- `Linux >= c524f9561c657b8af26dd4f67092b8928261aa62 < 122b6a8b0c75b5f808aa6ea68e97103330b9ffa7`
- `Linux >= 241f51931c35085449502c10f64fb3ecd6e02171 < 9798f7d41d85ff763afd1f1cc0533b5c416c8348`
- `Linux >= 241f51931c35085449502c10f64fb3ecd6e02171 < ab84fd7779a2a7ff5d2c8eac212c43733f56216e`
- `Linux >= 241f51931c35085449502c10f64fb3ecd6e02171 < 859bb1f4cb615d98c9c1ab2bd76ebb0b8fe46020`
- `Linux >= 241f51931c35085449502c10f64fb3ecd6e02171 < 9ca7053d6215d89c33f28893bfd1625a32919d3f`
- `Linux >= 6.1.9 < 6.1.191`
- `Linux 6.2`

## Remediation

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