PT-2025-13279 · Linux+3 · Linux Kernel+3

Published 2021-09-06 · Updated 2025-06-02 · CVE-2021-4454

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 versions prior to 5.14.0-rc7+

Description A vulnerability in the Linux kernel has been resolved, related to the j1939 session deactivate() function. The issue arises from an incorrect conclusion that j1939 session deactivate() should be called with a session ref-count of at least 2. However, in some concurrent scenarios, j1939 session deactivate can be called with the session ref-count less than 2, leading to a WARN ON ONCE. The problem occurs due to a race condition between j1939 xtp rx eoma and j1939 session deactivate.

Recommendations For Linux kernel versions prior to 5.14.0-rc7+, update to a version that includes the fix for the errant WARN ON ONCE in j1939 session deactivate(). As a temporary workaround, consider disabling the j1939 session deactivate() function until a patch is available. Restrict access to the j1939 module to minimize the risk of exploitation. Avoid using the j1939 session deactivate() function in concurrent scenarios until the issue is resolved.

Fix

RCE

Weakness Enumeration

CWE-399

CWE-20

Related Identifiers

BDU:2025-06396

CVE-2021-4454

OPENSUSE-SU-2025_1195-1

SUSE-SU-2025:1176-1

SUSE-SU-2025:1183-1

SUSE-SU-2025:1195-1

SUSE-SU-2025:1241-1

SUSE-SU-2025_1195-1

SUSE-SU-2025_1241-1

Affected Products

Astra Linux

Linux Kernel

Red Os

Suse

References · 1333

• https://security-tracker.debian.org/tracker/CVE-2021-4454 · Vendor Advisory
• https://bdu.fstec.ru/vul/2025-06396 · Security Note
• https://git.kernel.org/stable/c/1740a1e45eee65099a92fb502e1e67e63aad277d · Patch
• https://git.kernel.org/stable/c/d0553680f94c49bbe0e39eb50d033ba563b4212d · Patch
• https://osv.dev/vulnerability/SUSE-SU-2025:1241-1 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-4454 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-4454 · Vendor Advisory
• https://git.kernel.org/stable/c/9ab896775f98ff54b68512f345eed178bf961084 · Patch
• https://osv.dev/vulnerability/SUSE-SU-2025:1176-1 · Vendor Advisory
• https://git.kernel.org/stable/c/6950df42a03c9ac9290503ced3f371199cb68fa9 · Patch
• https://cve.org/CVERecord?id=CVE-2021-4454 · Security Note
• https://ubuntu.com/security/CVE-2021-4454 · Vendor Advisory
• https://git.kernel.org/stable/c/b6d44072117bba057d50f7a2f96e5d070c65926d · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-4454 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2025:1183-1 · Vendor Advisory