CVE-2025-37798

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

codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()

After making all ->qlen_notify() callbacks idempotent, now it is safe to remove the check of qlen!=0 from both fq_codel_dequeue() and codel_qdisc_dequeue().

This vulnerability is rated as Moderate severity because exploitation requires local privileges to manipulate network traffic control queuing disciplines, and the potential impact is restricted to a system crash (denial of service) without compromising confidentiality or data integrity. In standard Red Hat Enterprise Linux deployments, configuring custom traffic queue disciplines requires elevated privileges (such as the CAP_NET_ADMIN capability) or the ability to create unprivileged user and network namespaces. Consequently, unprivileged remote attackers cannot trigger this issue, and the local blast radius is limited to kernel instability.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.