Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: reject overly deep qdisc hierarchies Deep qdisc hierarchies can lead to excessive recursion in qdisc tree walkers and exhaust the kernel stack. The existing loop check does not cover the create-and-graft path, so a hierarchy can still be extended by creating a new child qdisc below an already deep parent. Store the hierarchy depth in struct Qdisc and update it when qdiscs are grafted. Reject new child qdiscs once the parent is already at the maximum allowed depth.
References8
- git.kernel.org/stable/c/08dc49df1527b09d9ea225a7265bbf6c237097bf
- git.kernel.org/stable/c/2759acf08a3454866660edcd3ef4e64139f254a6
- git.kernel.org/stable/c/8ca8cdb74939581339e1ae370193c0adb5a85336
- git.kernel.org/stable/c/9f69bb9fdaa2fe64b68bb62fb84d405784bee540
- git.kernel.org/stable/c/a4b14a4df29d36458a943f9b521ddd0f940363cc
- git.kernel.org/stable/c/a627d36c2a94e18c8c105ae68008786dfd85592e
- git.kernel.org/stable/c/dedd34b0f2310e28c5f6d4875cfbf4b7ed821c01
- git.kernel.org/stable/c/e2d658c6427844cee5bc654b436ca68d680b6148
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 3 · as of 9 November 2026
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