---
id: CVE-2026-74268
title: 'tcp: clear sock_ops cb flags before force-closing a child socket'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  tcp: clear sock_ops cb flags before force-closing a child socket

  A child socket inherits the listener's bpf_sock_ops_cb_flags via
  sk_clone_lock(). If its setup fails i…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= d44874910a26f3a8f81edf873a2473363f07f660 <
    5d5389b2c37ca00da61d1407618ebe15abae0c8b
  - >-
    Linux >= d44874910a26f3a8f81edf873a2473363f07f660 <
    9f30ba9aa0270a18fdd1e6cd426c480c35f7de9d
  - >-
    Linux >= d44874910a26f3a8f81edf873a2473363f07f660 <
    71e9c53220abd7f5a45aa4d5e5b420d3479f3a4f
  - >-
    Linux >= d44874910a26f3a8f81edf873a2473363f07f660 <
    9fffa6465851a1910a6e9cb7272787dd615b26b1
  - >-
    Linux >= d44874910a26f3a8f81edf873a2473363f07f660 <
    fe23d56e9266d58ba5c380f1970118eedeee0b68
  - >-
    Linux >= d44874910a26f3a8f81edf873a2473363f07f660 <
    ce311bd2e36596f0aa2c92ca86fb3e019ac57eae
  - >-
    Linux >= d44874910a26f3a8f81edf873a2473363f07f660 <
    8874dafc9099bc49c2e5ebba030f85d276421f92
  - >-
    Linux >= d44874910a26f3a8f81edf873a2473363f07f660 <
    990348e5bb457697c2f1f7f7b65154a3334d9d2b
  - Linux 4.16
published: '2026-08-15'
updated: '2026-09-14'
sourceUpdated: '2026-09-14T11:58:42.864Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-74268'
references:
  - url: 'https://git.kernel.org/stable/c/5d5389b2c37ca00da61d1407618ebe15abae0c8b'
  - url: 'https://git.kernel.org/stable/c/9f30ba9aa0270a18fdd1e6cd426c480c35f7de9d'
  - url: 'https://git.kernel.org/stable/c/71e9c53220abd7f5a45aa4d5e5b420d3479f3a4f'
  - url: 'https://git.kernel.org/stable/c/9fffa6465851a1910a6e9cb7272787dd615b26b1'
  - url: 'https://git.kernel.org/stable/c/fe23d56e9266d58ba5c380f1970118eedeee0b68'
  - url: 'https://git.kernel.org/stable/c/ce311bd2e36596f0aa2c92ca86fb3e019ac57eae'
  - url: 'https://git.kernel.org/stable/c/8874dafc9099bc49c2e5ebba030f85d276421f92'
  - url: 'https://git.kernel.org/stable/c/990348e5bb457697c2f1f7f7b65154a3334d9d2b'
tags:
  - cve.org
epss: 0.00755
epssPercentile: 0.53181
ingestedAt: '2026-09-14T15:23:07.456Z'
---

## Overview

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

tcp: clear sock_ops cb flags before force-closing a child socket

A child socket inherits the listener's bpf_sock_ops_cb_flags via
sk_clone_lock(). If its setup fails in tcp_v4_syn_recv_sock() /
tcp_v6_syn_recv_sock(), the child is freed through put_and_exit, where
inet_csk_prepare_forced_close() drops the socket lock and tcp_done() runs
without it.

If BPF_SOCK_OPS_STATE_CB_FLAG was inherited, tcp_done() -> tcp_set_state()
calls tcp_call_bpf(), which expects the lock and trips sock_owned_by_me():

  WARNING: include/net/sock.h:1799 at tcp_set_state+0x433/0x550
  RIP: 0010:tcp_set_state+0x433/0x550 include/net/sock.h:1799
  Call Trace:
   <IRQ>
   tcp_done+0xba/0x250 net/ipv4/tcp.c:5095
   tcp_v4_syn_recv_sock+0x850/0xa50 net/ipv4/tcp_ipv4.c:1787
   tcp_check_req+0xf30/0x1360 net/ipv4/tcp_minisocks.c:926
   tcp_v4_rcv+0x1047/0x1b50 net/ipv4/tcp_ipv4.c:2164
   </IRQ>

The child is freed before it is ever established, so it should run no
sock_ops callback. Clear its cb flags in inet_csk_prepare_for_destroy_sock(),
the common point for the IPv4, IPv6 and chtls forced-close paths and for the
MPTCP ->syn_recv_sock() failure path (dispose_child), which reaches tcp_done()
on a child that was never established too.

## Affected

- `Linux >= d44874910a26f3a8f81edf873a2473363f07f660 < 5d5389b2c37ca00da61d1407618ebe15abae0c8b`
- `Linux >= d44874910a26f3a8f81edf873a2473363f07f660 < 9f30ba9aa0270a18fdd1e6cd426c480c35f7de9d`
- `Linux >= d44874910a26f3a8f81edf873a2473363f07f660 < 71e9c53220abd7f5a45aa4d5e5b420d3479f3a4f`
- `Linux >= d44874910a26f3a8f81edf873a2473363f07f660 < 9fffa6465851a1910a6e9cb7272787dd615b26b1`
- `Linux >= d44874910a26f3a8f81edf873a2473363f07f660 < fe23d56e9266d58ba5c380f1970118eedeee0b68`
- `Linux >= d44874910a26f3a8f81edf873a2473363f07f660 < ce311bd2e36596f0aa2c92ca86fb3e019ac57eae`
- `Linux >= d44874910a26f3a8f81edf873a2473363f07f660 < 8874dafc9099bc49c2e5ebba030f85d276421f92`
- `Linux >= d44874910a26f3a8f81edf873a2473363f07f660 < 990348e5bb457697c2f1f7f7b65154a3334d9d2b`
- `Linux 4.16`

## Remediation

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