CVE-2025-38115 Details
Description
In the Linux kernel, the following vulnerability has been resolved: net_sched: sch_sfq: fix a potential crash on gso_skb handling SFQ has an assumption of always being able to queue at least one packet. However, after the blamed commit, sch->q.len can be inflated by packets in sch->gso_skb, and an enqueue() on an empty SFQ qdisc can be followed by an immediate drop. Fix sfq_drop() to properly clear q->tail in this situation. ip netns add lb ip link add dev to-lb type veth peer name in-lb netns lb ethtool -K to-lb tso off # force qdisc to requeue gso_skb ip netns exec lb ethtool -K in-lb gro on # enable NAPI ip link set dev to-lb up ip -netns lb link set dev in-lb up ip addr add dev to-lb 192.168.20.1/24 ip -netns lb addr add dev in-lb 192.168.20.2/24 tc qdisc replace dev to-lb root sfq limit 100 ip netns exec lb netserver netperf -H 192.168.20.2 -l 100 & netperf -H 192.168.20.2 -l 100 & netperf -H 192.168.20.2 -l 100 & netperf -H 192.168.20.2 -l 100 &
A denial-of-service vulnerability has been identified in the Linux kernel's Stochastic Fairness Queueing (SFQ) scheduling discipline. This issue arises because SFQ assumes it can always queue at least one packet. However, a recent change allows the queue length to be artificially inflated by packets in the 'gso_skb' (Generic Segmentation Offload) buffer. As a result, an 'enqueue' operation on an empty SFQ queue can lead to an immediate packet drop. The vulnerability can be reproduced by manipulating the 'gso_skb' buffer and the queueing discipline settings.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/5814a7fc3abb41f63f2d44c9d3ff9d4e62965b72 | kernel.org | Patch |
| https://git.kernel.org/stable/c/82448d4dcd8406dec688632a405fdcf7f170ec69 | kernel.org | Patch |
| https://git.kernel.org/stable/c/82ffbe7776d0ac084031f114167712269bf3d832 | kernel.org | Patch |
| https://git.kernel.org/stable/c/9c19498bdd7cb9d854bd3c54260f71cf7408495e | kernel.org | Patch |
| https://git.kernel.org/stable/c/b44f791f27b14c9eb6b907fbe51f2ba8bec32085 | kernel.org | Patch |
| https://git.kernel.org/stable/c/b4e9bab6011b9559b7c157b16b91ae46d4d8c533 | kernel.org | Patch |
| https://git.kernel.org/stable/c/c337efb20d6d9f9bbb4746f6b119917af5c886dc | kernel.org | Patch |
| https://git.kernel.org/stable/c/d1bc80da75c789f2f6830df89d91fb2f7a509943 | kernel.org | Patch |
| https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html | CVE | Third Party Advisory |
| https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html | CVE | Third Party Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-401 | Missing Release of Memory after Effective Lifetime | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 4.16, < 5.4.295 >= 5.5, < 5.10.239 >= 5.11, < 5.15.186 >= 5.16, < 6.1.142 >= 6.2, < 6.6.94 >= 6.7, < 6.12.34 >= 6.13, < 6.15.3 6.16 rc1 |
CPE
Remediation
| |
| debian debian linux | 11.0 |
CPE
Remediation
| |
Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 30, 2026 | CVE Modified | kernel.org |
| Jun 17, 2026 | CVE Modified | kernel.org |
| Dec 17, 2025 | Initial Analysis | [email protected] |
| Nov 3, 2025 | CVE Modified | CVE |
| Jul 3, 2025 | New CVE Received | kernel.org |