# CVE-2021-47203: scsi: lpfc: Fix list_add() corruption in lpfc_drain_txq()

> A list corruption bug in the lpfc SCSI driver allows attackers to cause memory corruption, potentially leading to system crashes or arbitrary code execution.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Apr 2024
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2021-47203, GHSA-84g6-j698-p58m, UBUNTU-CVE-2021-47203

## What is CVE-2021-47203?

CVE-2021-47203 is a high-severity memory corruption vulnerability in Linux kernel, published on 10 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

scsi: lpfc: Fix list_add() corruption in lpfc_drain_txq()

When parsing the txq list in lpfc_drain_txq(), the driver attempts to pass
the requests to the adapter. If such an attempt fails, a local "fail_msg"
string is set and a log message output.  The job is then added to a
completions list for cancellation.

Processing of any further jobs from the txq list continues, but since
"fail_msg" remains set, jobs are added to the completions list regardless
of whether a wqe was passed to the adapter.  If successfully added to
txcmplq, jobs are added to both lists resulting in list corruption.

Fix by clearing the fail_msg string after adding a job to the completions
list. This stops the subsequent jobs from being added to the completions
list unless they had an appropriate failure.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2021-47203?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-47203?

Apply the vendor's patch.

## Is CVE-2021-47203 being exploited?

There is no known exploitation of CVE-2021-47203 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47203 and fix it if it is affected.

What it is: CVE-2021-47203 is a high-severity memory corruption vulnerability in Linux kernel, published on 10 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-47203 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-47203/ (Markdown: https://insights.sbomify.com/CVE-2021-47203/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47203
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47203
- OSV: https://osv.dev/vulnerability/CVE-2021-47203

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47203/
Summaries are generated and may contain mistakes; the official description above is the record.