A new vulnerability has been identified in the Linux kernel versions up to 5.17.5. This security issue, known as CVE-2022-29968, affects the io_rw_init_file function in fs/io_uring.c, which fails to initialize the kiocb->private member. This post will provide a comprehensive overview of this vulnerability, including details about the vulnerable code snippet, references to the original sources, and information on how it can be exploited.

Code Snippet

The problematic code in question can be located within the io_rw_init_file function in the fs/io_uring.c file. The function does not properly initialize the kiocb->private field, as shown below:

static int io_rw_init_file(struct kiocb *req, struct io_kiocb *req, bool force)
{
    /* ... initializations ... */
    req->ki_filp = f;
    req->ki_pos = pos;
    /* Note: Missing initialization for kiocb->private */
    return ;
}

Faulty initialization of kiocb->private can lead to potential security risks and exploitable vulnerabilities.

Original References

This issue has been documented in the Linux kernel's official changelog, as well as the respective CVE database:

1. Linux kernel commit: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f351a5df800
2. CVE database entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-29968
3. NVD (National Vulnerability Database) entry: https://nvd.nist.gov/vuln/detail/CVE-2022-29968

Exploit Details

The uninitialized kiocb->private member can potentially be exploited to gain unauthorized access to sensitive memory contents or execute arbitrary code in the compromised system. This is due to the fact that uninitialized memory can contain sensitive information, previously allocated memory contents, or even pointers to other kernel structures.

An attacker may successfully exploit the vulnerable code by reading uninitialized memory in kiocb->private or corrupting its contents, depending on the specific use-case. The attacker may be able to take advantage of information leaks or perform arbitrary code execution as a result. It is essential to understand that Linux kernel vulnerabilities pose significant risks, as an attacker can abuse them to escalate their privileges, compromise the whole system, or even manipulate hardware components.

However, successfully exploiting this vulnerability would depend on factors such as the attacker's privileges, kernel configuration, mitigation techniques in place, and the target system's overall security posture.

Conclusion

CVE-2022-29968, the uninitialized kiocb->private member in the Linux kernel's io_rw_init_file function, poses a potential security risk. To secure your systems against this vulnerability, ensure that you are using an updated Linux kernel version and applying all available security patches. Additionally, implement other standard security best practices, such as proper access controls and continuous monitoring, to minimize the overall attack surface.

With this information and awareness, stay proactive in securing your systems against any potential exploits related to CVE-2022-29968.

Timeline

Published on: 05/02/2022 04:15:00 UTC
Last modified on: 07/15/2022 16:15:00 UTC