CVE-2025-38000
What it is
In the Linux kernel, the following vulnerability has been resolved: sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue() When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls the child qdisc's peek() operation before incrementing sch->q.qlen and sch->qstats.backlog. If the child qdisc uses qdisc_peek_dequeued(), this may trigger an immediate dequeue and potential packet drop. In such cases, qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backlog have not yet been updated, leading to inconsistent queue accounting. This can leave an empty HFSC class in the active list, causing further consequences like use-after-free. This patch fixes the bug by moving the increment of sch->q.qlen and sch->qstats.backlog before the call to the child qdisc's peek() operation. This ensures that queue length and backlog are always accurate when packet drops or dequeues are triggered during the peek.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Linux Kernel < 5.4.294
- Linux Kernel < 5.10.238
- Linux Kernel < 5.15.185
- Linux Kernel < 6.1.141
- Linux Kernel < 6.6.93
- Linux Kernel < 6.12.31
- Linux Kernel < 6.14.9
- Linux Kernel 6.15
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-38000.md and follow it. Check whether this project is affected by CVE-2025-38000. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/1034e3310752e8675e313f7271b348914008719a
- https://git.kernel.org/stable/c/3f3a22eebbc32b4fa8ce9c1d5f9db214b45b9335
- https://git.kernel.org/stable/c/3f981138109f63232a5fb7165938d4c945cc1b9d
- https://git.kernel.org/stable/c/49b21795b8e5654a7df3d910a12e1060da4c04cf
- https://git.kernel.org/stable/c/89c301e929a0db14ebd94b4d97764ce1d6981653
- https://git.kernel.org/stable/c/93c276942e75de0e5bc91576300d292e968f5a02
- https://git.kernel.org/stable/c/f1dde3eb17dc1b8bd07aed00004b1e05fc87a3d4
- https://git.kernel.org/stable/c/f9f593e34d2fb67644372c8f7b033bdc622ad228
References
- https://git.kernel.org/stable/c/1034e3310752e8675e313f7271b348914008719a
- https://git.kernel.org/stable/c/3f3a22eebbc32b4fa8ce9c1d5f9db214b45b9335
- https://git.kernel.org/stable/c/3f981138109f63232a5fb7165938d4c945cc1b9d
- https://git.kernel.org/stable/c/49b21795b8e5654a7df3d910a12e1060da4c04cf
- https://git.kernel.org/stable/c/89c301e929a0db14ebd94b4d97764ce1d6981653
- https://git.kernel.org/stable/c/93c276942e75de0e5bc91576300d292e968f5a02
- https://git.kernel.org/stable/c/f1dde3eb17dc1b8bd07aed00004b1e05fc87a3d4
- https://git.kernel.org/stable/c/f9f593e34d2fb67644372c8f7b033bdc622ad228
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html