cve/2021/CVE-2021-47132.md

### [CVE-2021-47132](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-47132)
![](https://img.shields.io/static/v1?label=Product&message=Linux&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=64b9cea7a0af%3C%20b9c78b1a9596%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### Description

In the Linux kernel, the following vulnerability has been resolved:mptcp: fix sk_forward_memory corruption on retransmissionMPTCP sk_forward_memory handling is a bit special, as such fieldis protected by the msk socket spin_lock, instead of the plainsocket lock.Currently we have a code path updating such field without handlingthe relevant lock:__mptcp_retrans() -> __mptcp_clean_una_wakeup()Several helpers in __mptcp_clean_una_wakeup() will updatesk_forward_alloc, possibly causing such field corruption, as reportedby Matthieu.Address the issue providing and using a new variant of blamed functionwhich explicitly acquires the msk spin lock.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/NaInSec/CVE-LIST