CVE-2024-53685: Ceph Vulnerability in Linux Kernel Resolved - Path Length Restriction Lifted Preventing DoS Attack

A recent vulnerability, tagged as CVE-2024-53685, was discovered in the Linux kernel associated with the Ceph distributed file system. The vulnerability can be exploited by malicious actors to launch a simple yet effective Denial of Service (DoS) attack, rendering the affected machine almost unusable.

Vulnerability Details

The vulnerability lies in the ceph_mdsc_build_path() function in Linux's Ceph implementation. When the function attempts to build a path that happens to be longer than PATH_MAX, it enters an endless retry loop, blocking the entire task and causing a DoS attack. The issue arises from the retry mechanism implemented therein.

Thankfully, the vulnerability has been resolved by eliminating the problematic retry mechanism and replacing it with an appropriate error message: "ENAMETOOLONG".

Exploit Details

The exploitation involves creating a path longer than PATH_MAX by abusing the ceph_mdsc_build_path() function. The system then enters an endless loop, preventing other tasks from executing, essentially causing a DoS attack. The attacker can incapacitate a targetted system using this simple exploit.

Code Snippet

The following code snippet illustrates the updated ceph_mdsc_build_path() function that mitigates CVE-2024-53685 vulnerability in Linux kernel:

int ceph_mdsc_build_path(struct ceph_mds_client *mdsc, struct ceph_mds_request *req)
{
    ...
    if (pathlen > PATH_MAX) {
        pr_warn("path too long

");
        return -ENAMETOOLONG;
    }
    ...
}

Original References

1. Ceph Distributed File System: https://ceph.com
2. Linux Kernel: https://www.kernel.org
3. CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-53685

Mitigation and Prevention

To prevent exploitation of this vulnerability, ensure your Linux kernel is updated to the latest version with the fix for CVE-2024-53685. Regularly reviewing system logs and monitoring system performance can also help detect any anomalies caused by potential attacks.

Conclusion

The CVE-2024-53685 vulnerability in the Linux kernel could have resulted in a simple and effective DoS attack against affected systems. However, the vulnerability has been resolved, and the risk of exploitation is now greatly reduced. Keeping your systems updated and following best security practices will further ensure protection against emerging threats.

Timeline

Published on: 01/11/2025 13:15:25 UTC
Last modified on: 02/26/2025 14:26:00 UTC