CVE-2025-21971

Source
https://nvd.nist.gov/vuln/detail/CVE-2025-21971
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-21971.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2025-21971
Downstream
Related
Published
2025-04-01T16:15:28Z
Modified
2025-08-09T20:01:27Z
Summary
[none]
Details

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

netsched: Prevent creation of classes with TCH_ROOT

The function qdisctreereducebacklog() uses TCHROOT as a termination condition when traversing up the qdisc tree to update parent backlog counters. However, if a class is created with classid TCH_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 TCHROOT (0xFFFFFFFF) across all qdisc types, as suggested by Jamal.

References

Affected packages