cve/2025/CVE-2025-21703.md

CVE-2025-21703

Description

In the Linux kernel, the following vulnerability has been resolved:netem: Update sch->q.qlen before qdisc_tree_reduce_backlog()qdisc_tree_reduce_backlog() notifies parent qdisc only if childqdisc becomes empty, therefore we need to reduce the backlog of thechild qdisc before calling it. Otherwise it would miss the opportunityto call cops->qlen_notify(), in the case of DRR, it resulted in UAFsince DRR uses ->qlen_notify() to maintain its active list.

POC

Reference

No PoCs from references.

Github

• https://github.com/ARPSyndicate/cve-scores
• https://github.com/XiaozaYa/linux-kernel-stack-pivoting-trick
• https://github.com/fkie-cad/nvd-json-data-feeds
• https://github.com/runwhen-contrib/helm-charts
• https://github.com/w4zu/Debian_security
• https://github.com/xairy/linux-kernel-exploitation