cve/2024/CVE-2024-26689.md

### [CVE-2024-26689](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-26689)
![](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=2.6.34%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=9030aaf9bf0a1eee47a154c316c789e959638b0f%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:ceph: prevent use-after-free in encode_cap_msg()In fs/ceph/caps.c, in encode_cap_msg(), "use after free" error wascaught by KASAN at this line - 'ceph_buffer_get(arg->xattr_buf);'. Thisimplies before the refcount could be increment here, it was freed.In same file, in "handle_cap_grant()" refcount is decremented by thisline - 'ceph_buffer_put(ci->i_xattrs.blob);'. It appears that a raceoccurred and resource was freed by the latter line before the formerline could increment it.encode_cap_msg() is called by __send_cap() and __send_cap() is called byceph_check_caps() after calling __prep_cap(). __prep_cap() is wherearg->xattr_buf is assigned to ci->i_xattrs.blob. This is the spot wherethe refcount must be increased to prevent "use after free" error.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/ARPSyndicate/cve-scores