cve/2021/CVE-2021-4155.md

### [CVE-2021-4155](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-4155)
![](https://img.shields.io/static/v1?label=Product&message=kernel&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=Fixed%20in%20Kernel%20v5.16%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-131%20-%20Incorrect%20Calculation%20of%20Buffer%20Size&color=brightgreen)

### Description

A data leak flaw was found in the way XFS_IOC_ALLOCSP IOCTL in the XFS filesystem allowed for size increase of files with unaligned size. A local attacker could use this flaw to leak data on the XFS filesystem otherwise not accessible to them.

### POC

#### Reference
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=983d8e60f50806f90534cc5373d0ce867e5aaf79

#### Github
- https://github.com/ARPSyndicate/cvemon
- https://github.com/lafayette96/CVE-Errata-Tool