Description
In the Linux kernel, the following vulnerability has been resolved:

sch_hfsc: make hfsc_qlen_notify() idempotent

hfsc_qlen_notify() is not idempotent either and not friendly
to its callers, like fq_codel_dequeue(). Let's make it idempotent
to ease qdisc_tree_reduce_backlog() callers' life:

1. update_vf() decreases cl->cl_nactive, so we can check whether it is
non-zero before calling it.

2. eltree_remove() always removes RB node cl->el_node, but we can use
RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe.
Published: 2025-07-04
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4271-1 linux-6.1 security update
Debian DLA Debian DLA DLA-4327-1 linux security update
EUVD EUVD EUVD-2025-20019 In the Linux kernel, the following vulnerability has been resolved: sch_hfsc: make hfsc_qlen_notify() idempotent hfsc_qlen_notify() is not idempotent either and not friendly to its callers, like fq_codel_dequeue(). Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers' life: 1. update_vf() decreases cl->cl_nactive, so we can check whether it is non-zero before calling it. 2. eltree_remove() always removes RB node cl->el_node, but we can use RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe.
Ubuntu USN Ubuntu USN USN-7653-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7655-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-7665-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7671-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7671-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7671-3 Linux kernel (IoT) vulnerabilities
Ubuntu USN Ubuntu USN USN-7686-1 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-7712-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7712-2 Linux kernel (Azure) vulnerabilities
History

Thu, 18 Dec 2025 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
Weaknesses CWE-459
NVD-CWE-noinfo
CPEs cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Mon, 03 Nov 2025 20:30:00 +0000

Type Values Removed Values Added
References

Mon, 03 Nov 2025 18:30:00 +0000

Type Values Removed Values Added
References

Thu, 28 Aug 2025 14:45:00 +0000


Sat, 05 Jul 2025 00:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Fri, 04 Jul 2025 13:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: sch_hfsc: make hfsc_qlen_notify() idempotent hfsc_qlen_notify() is not idempotent either and not friendly to its callers, like fq_codel_dequeue(). Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers' life: 1. update_vf() decreases cl->cl_nactive, so we can check whether it is non-zero before calling it. 2. eltree_remove() always removes RB node cl->el_node, but we can use RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe.
Title sch_hfsc: make hfsc_qlen_notify() idempotent
References

Subscriptions

Debian Debian Linux
Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-11T21:22:45.291Z

Reserved: 2025-04-16T04:51:23.992Z

Link: CVE-2025-38177

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-07-04T13:15:24.033

Modified: 2025-12-18T16:48:54.640

Link: CVE-2025-38177

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-07-04T00:00:00Z

Links: CVE-2025-38177 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-07-13T21:47:47Z

Weaknesses