CVE-2026-74268

Received Received - Intake

Linux kernel BPF sock_ops state callback use-after-free

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-74268

EUVD

EUVD-2026-59415

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a child socket inheriting BPF callback flags from its parent listener. When setup fails, the child socket is force-closed without proper locking, causing a race condition where tcp_done() executes without the socket lock. This triggers a warning due to BPF expecting the lock via sock_owned_by_me().

Detection Guidance

This vulnerability is specific to the Linux kernel and requires kernel-level inspection. Detection involves checking kernel logs for the described warning message or verifying if your kernel version includes the fix. Use uname -a to check your kernel version and dmesg | grep -i 'sock_owned_by_me' to search for related warnings.

Impact Analysis

This flaw could lead to kernel warnings or crashes during network operations, particularly when BPF socket operations are involved. It may cause instability in systems running affected Linux kernel versions, potentially disrupting network services or applications relying on BPF features.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a Linux kernel issue related to socket handling and BPF operations, which does not involve data processing, storage, or privacy concerns typically addressed by these regulations.

Mitigation Strategies

Update your Linux kernel to a patched version that includes the fix for CVE-2026-74268. Monitor kernel security advisories and apply updates promptly. If immediate patching is not possible, consider disabling BPF_SOCK_OPS_STATE_CB_FLAG temporarily as a workaround.

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