---
id: CVE-2023-53824
title: 'netlink: annotate lockless accesses to nlk->max_recvmsg_len'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netlink: annotate lockless accesses to nlk->max_recvmsg_len

  syzbot reported a data-race in data-race in netlink_recvmsg() [1]

  Indeed, netlink_recvmsg() can be run con…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 9063e21fb026c4966fc93261c18322214f9835eb <
    05c9e3fc93b02d18c3ab258d43350a6d44b40bbd
  - >-
    Linux >= 9063e21fb026c4966fc93261c18322214f9835eb <
    7cff4103be7c402ecc3e7bf8f95a64089e3c91b8
  - >-
    Linux >= 9063e21fb026c4966fc93261c18322214f9835eb <
    e3bcf2a77060bea4d8d09cb09d92c7056f07df5a
  - >-
    Linux >= 9063e21fb026c4966fc93261c18322214f9835eb <
    fc4ba13013ddaea8b11b88fd52b35449e2d9cf85
  - >-
    Linux >= 9063e21fb026c4966fc93261c18322214f9835eb <
    a1865f2e7d10dde00d35a2122b38d2e469ae67ed
  - Linux 3.15
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T21:37:29.602412Z'
published: '2025-12-09'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T21:41:36.860Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-53824'
references:
  - url: 'https://git.kernel.org/stable/c/05c9e3fc93b02d18c3ab258d43350a6d44b40bbd'
  - url: 'https://git.kernel.org/stable/c/7cff4103be7c402ecc3e7bf8f95a64089e3c91b8'
  - url: 'https://git.kernel.org/stable/c/e3bcf2a77060bea4d8d09cb09d92c7056f07df5a'
  - url: 'https://git.kernel.org/stable/c/fc4ba13013ddaea8b11b88fd52b35449e2d9cf85'
  - url: 'https://git.kernel.org/stable/c/a1865f2e7d10dde00d35a2122b38d2e469ae67ed'
tags:
  - cve.org
epss: 0.00194
epssPercentile: 0.08475
ingestedAt: '2026-10-15T22:48:25.423Z'
---

## Overview

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

netlink: annotate lockless accesses to nlk->max_recvmsg_len

syzbot reported a data-race in data-race in netlink_recvmsg() [1]

Indeed, netlink_recvmsg() can be run concurrently,
and netlink_dump() also needs protection.

[1]
BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg

read to 0xffff888141840b38 of 8 bytes by task 23057 on cpu 0:
netlink_recvmsg+0xea/0x730 net/netlink/af_netlink.c:1988
sock_recvmsg_nosec net/socket.c:1017 [inline]
sock_recvmsg net/socket.c:1038 [inline]
__sys_recvfrom+0x1ee/0x2e0 net/socket.c:2194
__do_sys_recvfrom net/socket.c:2212 [inline]
__se_sys_recvfrom net/socket.c:2208 [inline]
__x64_sys_recvfrom+0x78/0x90 net/socket.c:2208
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

write to 0xffff888141840b38 of 8 bytes by task 23037 on cpu 1:
netlink_recvmsg+0x114/0x730 net/netlink/af_netlink.c:1989
sock_recvmsg_nosec net/socket.c:1017 [inline]
sock_recvmsg net/socket.c:1038 [inline]
____sys_recvmsg+0x156/0x310 net/socket.c:2720
___sys_recvmsg net/socket.c:2762 [inline]
do_recvmmsg+0x2e5/0x710 net/socket.c:2856
__sys_recvmmsg net/socket.c:2935 [inline]
__do_sys_recvmmsg net/socket.c:2958 [inline]
__se_sys_recvmmsg net/socket.c:2951 [inline]
__x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000000 -> 0x0000000000001000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23037 Comm: syz-executor.2 Not tainted 6.3.0-rc4-syzkaller-00195-g5a57b48fdfcb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023

## Affected

- `Linux >= 9063e21fb026c4966fc93261c18322214f9835eb < 05c9e3fc93b02d18c3ab258d43350a6d44b40bbd`
- `Linux >= 9063e21fb026c4966fc93261c18322214f9835eb < 7cff4103be7c402ecc3e7bf8f95a64089e3c91b8`
- `Linux >= 9063e21fb026c4966fc93261c18322214f9835eb < e3bcf2a77060bea4d8d09cb09d92c7056f07df5a`
- `Linux >= 9063e21fb026c4966fc93261c18322214f9835eb < fc4ba13013ddaea8b11b88fd52b35449e2d9cf85`
- `Linux >= 9063e21fb026c4966fc93261c18322214f9835eb < a1865f2e7d10dde00d35a2122b38d2e469ae67ed`
- `Linux 3.15`

## Remediation

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