NULL Pointer Dereference Affecting kernel-cross-headers package, versions *


Severity

Recommended
low

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.03% (9th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about NULL Pointer Dereference vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-RHEL8-KERNELCROSSHEADERS-13493972
  • published8 Oct 2025
  • disclosed7 Oct 2025

Introduced: 7 Oct 2025

NewCVE-2022-50555  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:8 kernel-cross-headers.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-cross-headers package and not the kernel-cross-headers package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

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

tipc: fix a null-ptr-deref in tipc_topsrv_accept

syzbot found a crash in tipc_topsrv_accept:

KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] Workqueue: tipc_rcv tipc_topsrv_accept RIP: 0010:kernel_accept+0x22d/0x350 net/socket.c:3487 Call Trace: <TASK> tipc_topsrv_accept+0x197/0x280 net/tipc/topsrv.c:460 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

It was caused by srv->listener that might be set to null by tipc_topsrv_stop() in net .exit whereas it's still used in tipc_topsrv_accept() worker.

srv->listener is protected by srv->idr_lock in tipc_topsrv_stop(), so add a check for srv->listener under srv->idr_lock in tipc_topsrv_accept() to avoid the null-ptr-deref. To ensure the lsock is not released during the tipc_topsrv_accept(), move sock_release() after tipc_topsrv_work_stop() where it's waiting until the tipc_topsrv_accept worker to be done.

Note that sk_callback_lock is used to protect sk->sk_user_data instead of srv->listener, and it should check srv in tipc_topsrv_listener_data_ready() instead. This also ensures that no more tipc_topsrv_accept worker will be started after tipc_conn_close() is called in tipc_topsrv_stop() where it sets sk->sk_user_data to null.

CVSS Base Scores

version 3.1