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🛡️ CVE-2022-50555 — kernel

🟠 CVSS 7.8 — High ✅ No Known Exploit NVD
7.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

tipc: fix a null-ptr-deref in tipc_topsrv_accept

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.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Affected software

CVE-2022-50555 is recorded against 2 packages.

  • kernel (from 5.16.0 up to 6.0.7)
  • linux-kernel

Timeline and source

Published on 7 October 2025 and last revised on 12 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
github.com (Advisory)
nvd.nist.gov (Advisory)
git.kernel.org (Package)

Other advisories for this package

kernel has other advisories on record. If you are patching this one, these are worth checking on the same host:

CVE-2022-50555 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity High
CVSS Score 7.8
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2025-10-07
Updated 2026-08-20
Modified 2026-08-12

Affected Packages

Software From version Fixed in
kernel 5.16.0 6.0.7
linux-kernel — —

Similar Threats

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