PT-2025-49669 · Linux · Linux Kernel

Published 2025-12-09 · Updated 2026-01-28 · CVE-2023-53809

Positive Technologies (AI Summary)

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.2.0-rc5-00205-gc96618275234 #56

Description The Linux kernel contains a flaw in the l2tp implementation that can lead to a recursive deadlock within the l2tp tunnel register() function. This occurs when a file descriptor of a pppol2tp socket is passed as a file descriptor of a UDP socket. The issue is triggered by a specific program that attempts to connect using this configuration, resulting in a lock dependency warning and a potential system hang. The l2tp tunnel register() function and pppol2tp connect() are involved in the deadlock scenario.

Recommendations Update to a version later than 6.2.0-rc5-00205-gc96618275234 #56.

Exploit

Related Identifiers

CVE-2023-53809

RHSA-2023:2458

SUSE-SU-2026:0316-1

Affected Products

Linux Kernel

References · 333

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53809.json · Exploit
• https://cve.org/CVERecord?id=CVE-2023-53809 · Security Note
• https://osv.dev/vulnerability/CVE-2023-53809 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2023-53809 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2023-53809 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2023-53809 · Vendor Advisory
• https://osv.dev/vulnerability/BELL-CVE-2023-53809 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2023-53809 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2026:0316-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2023-53809 · Vendor Advisory
• https://suse.com/support/update/announcement/2026/suse-su-20260316-1 · Note
• https://bugzilla.suse.com/1254617 · Note
• https://bugzilla.suse.com/1253400 · Note
• https://suse.com/security/cve/CVE-2023-54032 · Note
• https://suse.com/security/cve/CVE-2023-53862 · Note