DEBIAN-CVE-2025-21971

Advisory lineage Upstream: 1 Downstream: 3
Upstream
CVE-2025-21971
Published: 01 Apr 2025, 16:15
Last modified:28 Apr 2026, 20:29

Vulnerability Summary

Overall Risk (default)
low
22/100
CVSS Score
5.5 MEDIUM
3.1 (osv_debian)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

01 Apr 2025, 16:15
Published
Vulnerability first disclosed
28 Apr 2026, 20:29
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: net_sched: Prevent creation of classes with TC_H_ROOT The function qdisc_tree_reduce_backlog() uses TC_H_ROOT as a termination condition when traversing up the qdisc tree to update parent backlog counters. However, if a class is created with classid TC_H_ROOT, the traversal terminates prematurely at this class instead of reaching the actual root qdisc, causing parent statistics to be incorrectly maintained. In case of DRR, this could lead to a crash as reported by Mingi Cho. Prevent the creation of any Qdisc class with classid TC_H_ROOT (0xFFFFFFFF) across all qdisc types, as suggested by Jamal.

CVSS Metrics

  • v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected Systems

  • debian•linux

    < 5.10.237-1 | < 6.1.133-1 | < 6.12.20-1 | < 6.12.20-1

  • debian•linux-6.1

    < 6.1.137-1~deb11u1

References (1)