CVE Catalog

CVE-2025-38177

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.16%

6th percentile - higher than 6% of all known CVEs

Summary

In the HFSC network scheduler in the Linux kernel, the hfsc_qlen_notify() function is not idempotent, which may cause issues when called from fq_codel_dequeue(). The fix adds checks to make the function safe for multiple calls.

Risk Assessment

The vulnerability may cause incorrect packet queuing behavior, potentially leading to packet loss or network instability.

Recommendation

Apply the Linux kernel patch that makes hfsc_qlen_notify() idempotent.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: sch_hfsc: make hfsc_qlen_notify() idempotent hfsc_qlen_notify() is not idempotent either and not friendly to its callers, like fq_codel_dequeue(). Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers' life: 1. update_vf() decreases cl->cl_nactive, so we can check whether it is non-zero before calling it. 2. eltree_remove() always removes RB node cl->el_node, but we can use RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS