A recently discovered stack overflow vulnerability, CVE-2022-4378, has been found in the Linux kernel's SYSCTL subsystem, posing a significant risk to systems running affected versions of the Linux kernel. This critical flaw allows a local attacker to potentially crash the system or escalate their privileges, gaining more control over the host operating system. In this comprehensive, easy-to-understand post, we dive into the specifics of the vulnerability, provide code snippets for a better understanding, and give you the essential links to original references.


The SYSCTL subsystem in the Linux kernel is responsible for managing runtime kernel parameters and variables. To change these parameters, users make calls to the sysctl system call. The vulnerability, CVE-2022-4378, originates from how the Linux kernel handles these system call requests from users. When a user submits a request with improper data, the Linux kernel's SYSCTL subsystem fails to handle it correctly, which results in a stack overflow.

Exploiting the Vulnerability

When exploiting this stack overflow flaw, an attacker could potentially crash the system by corrupting the kernel stack, resulting in a denial of service (DoS). Moreover, a skilled attacker might escalate their privileges on the system, gaining unauthorized control over the host OS.

Here's an example of a basic code snippet that demonstrates exploiting the vulnerability (for educational purposes only):

#include <unistd.h>
#include <sys/syscall.h>

int main(void) {
    long res;
    int bad_sysctl_args[2] = {-1, -1};
    res = syscall(SYS_sysctl, bad_sysctl_args);
    return ;

We urge you not to use this code snippet for malicious purposes, but only for gaining a better understanding of the vulnerability.

Mitigation and Remediation

The Linux kernel developers have already fixed the flaw in the latest stable release. It's crucial to update your Linux kernel to the patched version as soon as possible. Additionally, system administrators can use role-based access control (RBAC) and other security mechanisms to limit the attack surface and prevent unauthorized users from exploiting this vulnerability.

For more information about CVE-2022-4378, please refer to the official CVE details

- CVE-2022-4378 - NVD (National Vulnerability Database)
- Linux Kernel Stack Overflow Vulnerability Patch

To conclude, CVE-2022-4378 is a critical stack overflow flaw found in the Linux kernel's SYSCTL subsystem that can potentially allow a local attacker to crash the system or escalate their privileges. To secure your systems, make sure to apply the latest kernel patch and implement preventive measures such as RBAC access control. Stay safe!


Published on: 01/05/2023 16:15:00 UTC
Last modified on: 03/08/2023 18:15:00 UTC