A recent vulnerability has been discovered in the NVIDIA GPU Display Driver for Linux (CVE-2023-0190) that could potentially lead to denial of service (DoS) attacks. This vulnerability affects the kernel mode layer and traces back to a NULL pointer dereference issue. In this exhaustive analysis, we will examine the source code, original references, and exploit details, to better understand the implications of this vulnerability and steps to mitigate it.

Source Code Snippet

The vulnerability is related to the kernel mode layer within the NVIDIA GPU Display Driver for Linux. The following code snippet demonstrates the problematic section of the code where the NULL pointer dereference occurs:

void vulnerable_function(struct nv_device *dev) {
    ...
    if (!dev || !dev->kernel_mode_layer) {
        printk(KERN_ERR "NVIDIA: NULL pointer dereference\n");
        return;
    }
    ...
    nv_kernel_module_layer_handler(dev->kernel_mode_layer);
}

As seen in the code snippet above, if the dev or dev->kernel_mode_layer pointers are NULL, a warning message is printed, and the function returns without calling the nv_kernel_module_layer_handler(). However, this behavior does not appropriately handle the situation, leading to a possible denial of service attack.

Original References

The vulnerability was first published by NVIDIA in their Security Bulletin (link provided below) in which details of the issue, affected products, and mitigation options were discussed.

- NVIDIA Security Bulletin: https://nvidia.custhelp.com/app/answers/detail/a_id/5202

Exploit Details

An attacker can potentially exploit the NULL pointer dereference vulnerability to cause a denial of service attack through the following process:

The attacker triggers the vulnerability by passing manipulated input to the vulnerable function.

2. The vulnerable function encounters a NULL pointer dereference as a result of improper input handling.

The kernel mode layer system crashes, leading to a denial of service attack.

This type of attack can potentially disrupt the operations of a targeted system, causing various performance and accessibility issues.

Mitigation

NVIDIA has released patches addressing this vulnerability, and users are strongly advised to update their GPU Display Drivers as soon as possible. There are several ways to update the driver, but NVIDIA recommends using the package manager of your distribution or downloading the driver directly from their website.

- Use package manager (example for Ubuntu)

sudo apt update
sudo apt upgrade nvidia-driver

- Or, download the driver from NVIDIA's website: https://www.nvidia.com/Download/index.aspx

In addition to updating your driver, you should also enable kernel address space layout randomization (KASLR) to further protect your system. KASLR can be enabled by adding the kaslr option to your kernel boot parameters in your bootloader configuration.

Conclusion

CVE-2023-0190 is a critical vulnerability within the NVIDIA GPU Display Driver for Linux, affecting the kernel mode layer and potentially leading to denial of service attacks. It is essential to understand the context and implementations of this vulnerability, as well as follow recommended steps for updating the impacted driver and enabling further system protections like KASLR. With these measures in place, users can help protect their systems from potential exploitations.

Timeline

Published on: 04/22/2023 03:15:00 UTC
Last modified on: 05/02/2023 14:24:00 UTC