CVE-2025-68325
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-18

Last updated on: 2025-12-19

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_cake: Fix incorrect qlen reduction in cake_drop In cake_drop(), qdisc_tree_reduce_backlog() is used to update the qlen and backlog of the qdisc hierarchy. Its caller, cake_enqueue(), assumes that the parent qdisc will enqueue the current packet. However, this assumption breaks when cake_enqueue() returns NET_XMIT_CN: the parent qdisc stops enqueuing current packet, leaving the tree qlen/backlog accounting inconsistent. This mismatch can lead to a NULL dereference (e.g., when the parent Qdisc is qfq_qdisc). This patch computes the qlen/backlog delta in a more robust way by observing the difference before and after the series of cake_drop() calls, and then compensates the qdisc tree accounting if cake_enqueue() returns NET_XMIT_CN. To ensure correct compensation when ACK thinning is enabled, a new variable is introduced to keep qlen unchanged.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2025-12-18
Last Modified
2025-12-19
Generated
2026-06-16
AI Q&A
2025-12-18
EPSS Evaluated
2026-06-15
NVD
CVE-2025-68325
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Executive Summary

This vulnerability is in the Linux kernel's network scheduler component called sch_cake. It involves incorrect queue length (qlen) reduction in the cake_drop function. Specifically, when cake_enqueue() returns NET_XMIT_CN, the parent queueing discipline (qdisc) stops enqueuing the current packet, causing the qlen and backlog accounting in the qdisc hierarchy to become inconsistent. This inconsistency can lead to a NULL pointer dereference, potentially causing a kernel crash or instability. The fix involves more robustly computing the qlen/backlog changes and compensating the accounting when cake_enqueue() returns NET_XMIT_CN.

Impact Analysis

This vulnerability can cause a NULL pointer dereference in the Linux kernel's network scheduler, which may lead to kernel crashes or system instability. Such crashes can disrupt network operations and potentially cause denial of service on affected systems.

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2025-68325. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart