CVEs-PoC/2020/CVE-2020-29374.md

### [CVE-2020-29374](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-29374)
![](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 5.7.3, related to mm/gup.c and mm/huge_memory.c. The get_user_pages (aka gup) implementation, when used for a copy-on-write page, does not properly consider the semantics of read operations and therefore can grant unintended write access, aka CID-17839856fd58.

### POC

#### Reference
- http://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.html
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.7.3
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=17839856fd588f4ab6b789f482ed3ffd7c403e1f

#### Github
- https://github.com/Moonshieldgru/Moonshieldgru
- https://github.com/defgsus/good-github