PT-2025-18885 · Linux+4 · Linux Kernel+4

Published 2023-11-07 · Updated 2026-02-02 · CVE-2023-53121

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A vulnerability in the Linux kernel has been resolved. The issue arises when tcp make synack() is called from process context, potentially leading to the use of this cpu add() in preemptible code. This can cause a bug when tcp rtx synack() calls tcp make synack(), which touches per-CPU variables with preemption enabled. The bug results in a call trace that includes functions such as tcp v6 send synack(), tcp rtx synack(), and tcp check req(). To avoid this issue, it is recommended to use TCP INC STATS() instead of TCP INC STATS(), as the former is safe to be called from context switch.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Related Identifiers

ALSA-2025_16880

CVE-2023-53121

RHSA-2023:6583

RHSA-2023_6583

SUSE-SU-2025:01983-1

SUSE-SU-2025_01983-1

Affected Products

Astra Linux

Linux Kernel

Red Hat

Red Os

Suse

References · 380

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53121.json · Exploit
• https://osv.dev/vulnerability/DEBIAN-CVE-2023-53121 · Vendor Advisory
• https://git.kernel.org/stable/c/bced3f7db95ff2e6ca29dc4d1c9751ab5e736a09 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2023-53121 · Security Note
• https://osv.dev/vulnerability/CVE-2023-53121 · Vendor Advisory
• https://git.kernel.org/stable/c/442aa78ed70188b21ccd8669738448702c0a3281 · Patch
• https://git.kernel.org/stable/c/ad07290d63ff6689f50565b02f5b6f34ec15a5ca · Patch
• https://osv.dev/vulnerability/BELL-CVE-2023-53121 · Vendor Advisory
• https://git.kernel.org/stable/c/e23ca307745be3df7fe9762f3e2a7e311a57852e · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2023-53121 · Vendor Advisory
• https://ubuntu.com/security/CVE-2023-53121 · Vendor Advisory
• https://git.kernel.org/stable/c/77ad58bca0119e8cc3e0e9d91a3f22caa66e4dfa · Patch
• https://cve.org/CVERecord?id=CVE-2023-53121 · Security Note
• https://osv.dev/vulnerability/SUSE-SU-2025:01983-1 · Vendor Advisory
• https://git.kernel.org/stable/c/7613cde8c0c1f02a7ec2e1d536c01b65b135fc1c · Patch