cve/2021/CVE-2021-28964.md

### [CVE-2021-28964](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-28964)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### Description

A race condition was discovered in get_old_root in fs/btrfs/ctree.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (BUG) because of a lack of locking on an extent buffer before a cloning operation, aka CID-dbcc7d57bffc.

### POC

#### Reference
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dbcc7d57bffc0c8cac9dac11bec548597d59a6a5

#### Github
- https://github.com/ARPSyndicate/cvemon