cve/2019/CVE-2019-20812.md

### [CVE-2019-20812](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-20812)
![](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

An issue was discovered in the Linux kernel before 5.4.7. The prb_calc_retire_blk_tmo() function in net/packet/af_packet.c can result in a denial of service (CPU consumption and soft lockup) in a certain failure case involving TPACKET_V3, aka CID-b43d1f9f7067.

### POC

#### Reference
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.7
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b43d1f9f7067c6759b1051e8ecb84e82cef569fe
- https://www.oracle.com/security-alerts/cpuApr2021.html

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