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

l2tp: close all race conditions in l2tp_tunnel_register()

The code in l2tp_tunnel_register() is racy in several ways:

1. It modifies the tunnel socket _after_ publishing it.

2. It calls setup_udp_tunnel_sock() on an existing socket without
locking.

3. It changes sock lock class on fly, which triggers many syzbot
reports.

This patch amends all of them by moving socket initialization code
before publishing and under sock lock. As suggested by Jakub, the
l2tp lockdep class is not necessary as we can just switch to
bh_lock_sock_nested().

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00016.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel
Redhat
  • Enterprise Linux

Configuration 1 [-]

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.2:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.2:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.2:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.2:rc4:*:*:*:*:*:*
Package CPE Advisory Released Date
Red Hat Enterprise Linux 9
kernel-0:5.14.0-284.11.1.el9_2 cpe:/a:redhat:enterprise_linux:9 RHSA-2023:2458 2023-05-09T00:00:00Z
kernel-0:5.14.0-284.11.1.el9_2 cpe:/o:redhat:enterprise_linux:9 RHSA-2023:2458 2023-05-09T00:00:00Z

No data.

Advisories
Source ID Title
EUVD EUVD EUVD-2023-59700 In the Linux kernel, the following vulnerability has been resolved: l2tp: close all race conditions in l2tp_tunnel_register() The code in l2tp_tunnel_register() is racy in several ways: 1. It modifies the tunnel socket _after_ publishing it. 2. It calls setup_udp_tunnel_sock() on an existing socket without locking. 3. It changes sock lock class on fly, which triggers many syzbot reports. This patch amends all of them by moving socket initialization code before publishing and under sock lock. As suggested by Jakub, the l2tp lockdep class is not necessary as we can just switch to bh_lock_sock_nested().
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/0b2c59720e65885a394a017d0cf9cab118914682 cve-icon cve-icon
https://git.kernel.org/stable/c/2d77e5c0ad79004b5ef901895437e9cce6dfcc7e cve-icon cve-icon
https://git.kernel.org/stable/c/77e8ed776cdb1a24b2aab8fe7c6f1f154235e1ce cve-icon cve-icon
https://git.kernel.org/stable/c/cef0845b6dcfa2f6c2c832e7f9622551456c741d cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025032717-CVE-2023-53020-1042@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2023-53020 cve-icon
https://www.cve.org/CVERecord?id=CVE-2023-53020 cve-icon
History

Wed, 01 Oct 2025 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 06 May 2025 02:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux

Tue, 15 Apr 2025 20:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-362
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.2:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.2:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.2:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.2:rc4:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

 cvssV3_1

{'score': 4.7, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'}

Fri, 28 Mar 2025 13:45:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low

Thu, 27 Mar 2025 17:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: l2tp: close all race conditions in l2tp_tunnel_register() The code in l2tp_tunnel_register() is racy in several ways: 1. It modifies the tunnel socket _after_ publishing it. 2. It calls setup_udp_tunnel_sock() on an existing socket without locking. 3. It changes sock lock class on fly, which triggers many syzbot reports. This patch amends all of them by moving socket initialization code before publishing and under sock lock. As suggested by Jakub, the l2tp lockdep class is not necessary as we can just switch to bh_lock_sock_nested().
Title l2tp: close all race conditions in l2tp_tunnel_register()
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-10-01T17:19:20.613Z

Reserved: 2025-03-27T16:40:15.752Z

Link: CVE-2023-53020

cve-icon Vulnrichment

Updated: 2025-10-01T14:37:04.768Z

cve-icon NVD

Status : Modified

Published: 2025-03-27T17:15:51.457

Modified: 2025-10-01T18:15:36.123

Link: CVE-2023-53020

cve-icon Redhat

Severity : Low

Publid Date: 2025-03-27T00:00:00Z

Links: CVE-2023-53020 - Bugzilla

cve-icon OpenCVE Enrichment

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