PT-2025-4364 · Linux+7 · Linux Kernel+7

Michal Luczaj

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Published

2025-01-10

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Updated

2026-02-18

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CVE-2025-21683

CVSS v3.1

5.5

Medium

VectorAV: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 The issue is related to a memory leak in the bpf sk select reuseport() function. This leak occurs because a socket's reference is not dropped in error paths, potentially leading to a denial of service. The problem arises when a lookup in sockmap returns a TCP ESTABLISHED socket that had SO ATTACH REUSEPORT EBPF set before it was established, indicating that a non-NULL sk reuseport cb does not imply a non-refcounted socket. Technical details include the sk reuseport attach bpf() and sk setsockopt() functions being involved in the issue. There is no information provided about the estimated number of potentially affected devices or real-world incidents where this issue was exploited.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Memory Leak

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Weakness Enumeration

Related Identifiers

ALT-PU-2025-12647
ALT-PU-2025-3467
ALT-PU-2025-3500
AZL-56268
AZL-56333
BDU:2025-01462
CVE-2025-21683
DLA-4075-1
DLA-4076-1
DSA-5860-1
OESA-2025-1371
OESA-2025-1372
OPENSUSE-SU-2025_01614-1
OPENSUSE-SU-2025_01707-1
SUSE-SU-2025:01614-1
SUSE-SU-2025:01707-1
SUSE-SU-2025:01919-1
SUSE-SU-2025:01951-1
SUSE-SU-2025:01964-1
SUSE-SU-2025:01967-1
SUSE-SU-2025:01972-1
SUSE-SU-2025:20343-1
SUSE-SU-2025:20344-1
SUSE-SU-2025:20354-1
SUSE-SU-2025:20355-1
SUSE-SU-2025_01614-1
SUSE-SU-2025_01707-1
SUSE-SU-2025_01951-1
SUSE-SU-2025_01964-1
SUSE-SU-2025_01967-1
SUSE-SU-2025_01972-1
USN-7387-1
USN-7387-2
USN-7387-3
USN-7388-1
USN-7389-1
USN-7390-1
USN-7407-1
USN-7421-1
USN-7445-1
USN-7448-1
USN-7458-1
USN-7459-1
USN-7459-2
USN-7595-1
USN-7595-2
USN-7595-3
USN-7595-4
USN-7595-5
USN-7596-1
USN-7596-2
USN-7653-1

Affected Products

Alt Linux
Astra Linux
Debian
Linuxmint
Linux Kernel
Red Os
Suse
Ubuntu