Vulnerability in Linux

CVE-2025-38177

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.

EPSS: 0.002 (5.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-38177?
CVE-2025-38177 is a high-severity vulnerability in Linux, classified under Incomplete Cleanup. CVSS score: 7.8/10. Published 2025-07-04.
How severe is CVE-2025-38177?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-38177 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.