---
id: CVE-2022-49420
title: 'net: annotate races around sk->sk_bound_dev_if'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: annotate races around sk->sk_bound_dev_if

  UDP sendmsg() is lockless, and reads sk->sk_bound_dev_if while
  this field can be changed by another thread.

  Adds minima…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    20b2f61797873a2b18b5ff1a304ad2674fa1e0a5
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    4c971d2f3548e4f11b1460ac048f5307e4b39fdb
  - Linux < 5.18.3
  - Linux (all versions)
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T19:45:26.838615Z'
published: '2025-02-26'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T19:49:39.353Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2022-49420'
references:
  - url: 'https://git.kernel.org/stable/c/20b2f61797873a2b18b5ff1a304ad2674fa1e0a5'
  - url: 'https://git.kernel.org/stable/c/4c971d2f3548e4f11b1460ac048f5307e4b39fdb'
tags:
  - cve.org
epss: 0.00228
epssPercentile: 0.13695
ingestedAt: '2026-11-05T22:38:31.574Z'
---

## Overview

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

net: annotate races around sk->sk_bound_dev_if

UDP sendmsg() is lockless, and reads sk->sk_bound_dev_if while
this field can be changed by another thread.

Adds minimal annotations to avoid KCSAN splats for UDP.
Following patches will add more annotations to potential lockless readers.

BUG: KCSAN: data-race in __ip6_datagram_connect / udpv6_sendmsg

write to 0xffff888136d47a94 of 4 bytes by task 7681 on cpu 0:
 __ip6_datagram_connect+0x6e2/0x930 net/ipv6/datagram.c:221
 ip6_datagram_connect+0x2a/0x40 net/ipv6/datagram.c:272
 inet_dgram_connect+0x107/0x190 net/ipv4/af_inet.c:576
 __sys_connect_file net/socket.c:1900 [inline]
 __sys_connect+0x197/0x1b0 net/socket.c:1917
 __do_sys_connect net/socket.c:1927 [inline]
 __se_sys_connect net/socket.c:1924 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1924
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888136d47a94 of 4 bytes by task 7670 on cpu 1:
 udpv6_sendmsg+0xc60/0x16e0 net/ipv6/udp.c:1436
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:652
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmmsg+0x267/0x4c0 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000 -> 0xffffff9b

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7670 Comm: syz-executor.3 Tainted: G        W         5.18.0-rc1-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

I chose to not add Fixes: tag because race has minor consequences
and stable teams busy enough.

## Affected

- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 20b2f61797873a2b18b5ff1a304ad2674fa1e0a5`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 4c971d2f3548e4f11b1460ac048f5307e4b39fdb`
- `Linux < 5.18.3`
- `Linux (all versions)`

## Remediation

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