cve/2024/CVE-2024-50199.md

### [CVE-2024-50199](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-50199)
![](https://img.shields.io/static/v1?label=Product&message=Linux&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=0fe6e20b9c4c53b3e97096ee73a0857f60aad43f%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=2.6.36%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=blue)

### Description

In the Linux kernel, the following vulnerability has been resolved:mm/swapfile: skip HugeTLB pages for unuse_vmaI got a bad pud error and lost a 1GB HugeTLB when calling swapoff.  Theproblem can be reproduced by the following steps: 1. Allocate an anonymous 1GB HugeTLB and some other anonymous memory. 2. Swapout the above anonymous memory. 3. run swapoff and we will get a bad pud error in kernel message:  mm/pgtable-generic.c:42: bad pud 00000000743d215d(84000001400000e7)We can tell that pud_clear_bad is called by pud_none_or_clear_bad inunuse_pud_range() by ftrace.  And therefore the HugeTLB pages will neverbe freed because we lost it from page table.  We can skip HugeTLB pagesfor unuse_vma to fix it.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/w4zu/Debian_security