cve/2024/CVE-2024-49889.md

### [CVE-2024-49889](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-49889)
![](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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2%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:ext4: avoid use-after-free in ext4_ext_show_leaf()In ext4_find_extent(), path may be freed by error or be reallocated, sousing a previously saved *ppath may have been freed and thus may triggeruse-after-free, as follows:ext4_split_extent  path = *ppath;  ext4_split_extent_at(ppath)  path = ext4_find_extent(ppath)  ext4_split_extent_at(ppath)    // ext4_find_extent fails to free path    // but zeroout succeeds  ext4_ext_show_leaf(inode, path)    eh = path[depth].p_hdr    // path use-after-free !!!Similar to ext4_split_extent_at(), we use *ppath directly as an input toext4_ext_show_leaf(). Fix a spelling error by the way.Same problem in ext4_ext_handle_unwritten_extents(). Since 'path' is onlyused in ext4_ext_show_leaf(), remove 'path' and use *ppath directly.This issue is triggered only when EXT_DEBUG is defined and therefore doesnot affect functionality.

### POC

#### Reference
No PoCs from references.

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