PT-2025-40649 · Systemd+6 · Systemd+6

Published

2025-10-04

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Updated

2026-05-07

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CVE-2025-39953

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 A hung task can occur during cgroup testing when repeatedly mounting/unmounting perf event and net prio controllers with systemd.unified cgroup hierarchy=1. The hang manifests in cgroup lock and drain offline() during root destruction. The root cause is a deadlock situation where root destruction waits for offline completion, but offline work is blocked behind root destruction in cgroup destroy wq due to a limited number of active workers. The issue arises when a dying perf event CSS gets queued for offline after root destruction. The solution involves splitting cgroup destroy wq into three dedicated workqueues: cgroup offline wq, cgroup release wq, and cgroup free wq. This separation eliminates blocking in the CSS free path while waiting for offline operations to complete.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Allocation of Resources Without Limits

Weakness Enumeration

Related Identifiers

AZL-68165
AZL-75179
BDU:2026-02758
CVE-2025-39953
DLA-4379-1
DLA-4404-1
DSA-6053-1
ECHO-D30B-8D7C-2B75
MGASA-2025-0309
MGASA-2025-0310
OESA-2025-2465
OESA-2025-2466
OESA-2025-2467
USN-8033-1
USN-8033-2
USN-8033-3
USN-8033-4
USN-8033-5
USN-8033-6
USN-8033-7
USN-8033-8
USN-8034-1
USN-8034-2
USN-8095-1
USN-8095-2
USN-8095-3
USN-8095-4
USN-8095-5
USN-8100-1
USN-8125-1
USN-8126-1
USN-8141-1
USN-8163-1
USN-8163-2
USN-8165-1
USN-8243-1
USN-8261-1

Affected Products

Debian
Linuxmint
Linux Kernel
Ubuntu
Net Prio
Perf Event
Systemd