# ubifs: Fix deadlock in concurrent rename whiteout and inode writeback

CVE record · `CVE-2021-47637`

- **Identifiers:** `CVE-2021-47637`
- **State:** Confirmed
- **Severity:** CVSS 5.5 Medium
- **Critical:** No
- **CNA:** Linux
- **Weakness (CWE):** [CWE-667](https://cwe.mitre.org/data/definitions/667.html)
- **Tags:** [CWE-667](https://agentprime.io/advisories/tag/cwe-667.md)
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 26 Feb 2025
- **Updated:** 11 May 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 26 Feb 2025, 01:54 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 to before 9dddc8211430fb851ddf0b168e3a00c6f66cc185` (git)
  - affected: `9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 to before 37bdf1ad592555ecda1d55b89f6e393e4c0589d1` (git)
  - affected: `9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 to before 83e42a78428fc354f5e2049935b84c8d8d29b787` (git)
  - affected: `9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 to before c58af8564a7b08757173009030b74baf4b2b762b` (git)
  - affected: `9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 to before 70e9090acc32348cedc5def0cd6d5c126efc97b9` (git)
  - affected: `9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 to before 8b278c8dcfb565cb65eceb62a38cbf7a7c326db5` (git)
  - affected: `9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 to before afd427048047e8efdedab30e8888044e2be5aa9c` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `4.9`
  - unaffected: `before 4.9` (semver)
  - unaffected: `4.19.238 to 4.19.*, inclusive` (semver)
  - unaffected: `5.4.189 to 5.4.*, inclusive` (semver)
  - unaffected: `5.10.110 to 5.10.*, inclusive` (semver)
  - unaffected: `5.15.33 to 5.15.*, inclusive` (semver)
  - unaffected: `5.16.19 to 5.16.*, inclusive` (semver)
  - unaffected: `5.17.2 to 5.17.*, inclusive` (semver)
  - unaffected: `5.18 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 5.5 Medium, CVSS 3.1: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`, from ADP (CISA-ADP)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0019, the 9th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 26 Feb 2025. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2021-47637](https://www.cve.org/CVERecord?id=CVE-2021-47637)
- [NVD: CVE-2021-47637](https://nvd.nist.gov/vuln/detail/CVE-2021-47637)

### References from the CNA

- <https://git.kernel.org/stable/c/9dddc8211430fb851ddf0b168e3a00c6f66cc185>
- <https://git.kernel.org/stable/c/37bdf1ad592555ecda1d55b89f6e393e4c0589d1>
- <https://git.kernel.org/stable/c/83e42a78428fc354f5e2049935b84c8d8d29b787>
- <https://git.kernel.org/stable/c/c58af8564a7b08757173009030b74baf4b2b762b>
- <https://git.kernel.org/stable/c/70e9090acc32348cedc5def0cd6d5c126efc97b9>
- <https://git.kernel.org/stable/c/8b278c8dcfb565cb65eceb62a38cbf7a7c326db5>
- <https://git.kernel.org/stable/c/afd427048047e8efdedab30e8888044e2be5aa9c>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2021-47637>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2021-47637/>. Everything for agents: <https://agentprime.io/llms.txt>.