CVEvulnerability

CVE-2025-21971

5.5 MEDIUM Published 2025-04-01 Modified 2026-10-15 Official page ↗
Status
Modified
Published
2025-04-01
Last modified
2026-10-15
Assigner
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1 ([email protected])
5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-835

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.

Affected configurations

• linux linux kernel (>= 2.6.26 < 5.4.292) • linux linux kernel (>= 5.5 < 5.10.236) • linux linux kernel (>= 5.11 < 5.15.180) • linux linux kernel (>= 5.16 < 6.1.132) • linux linux kernel (>= 6.2 < 6.6.84) • linux linux kernel (>= 6.7 < 6.12.20) • linux linux kernel (>= 6.13 < 6.13.8) • linux linux kernel 2.6.25 • linux linux kernel 6.14

Related

Weakness · CWE (1)

  • CWE-835 Loop with Unreachable Exit Condition weakness

References