CVE-2023-52918 - Linux Kernel Media PCI CX23885 Vulnerability Resolved with Proper NULL Pointer Check

Hello everyone!

As we all rely on various Linux distributions in our daily lives, it's essential to keep abreast of the latest vulnerabilities that have been patched in the kernel. Today, we'll be delving into a recently addressed issue in the Linux kernel vulnerability CVE-2023-52918 that pertains to media PCI drivers for Conexant CX23885 and what was done to fix it.

In essence, the core problem lies in the 'media: pci: cx23885' component of the Linux kernel. This component is responsible for managing the video capturing and streaming hardware based on the Conexant CX23885 chipset, which can be found in some PCIe video capture cards. The vulnerability revolves around the function 'cx23885_vdev_init()' that could potentially return a NULL pointer. When this happened, the next line would then erroneously use the same NULL pointer without performing a check, ultimately leading to the entire system crashing or freezing.

You can browse the original kernel mailing list references for this vulnerability in CVE-2023-52918 here' function returns a NULL pointer. Here is the code snippet of the applied fix:

@@ -2697,7 +2697,10 @@ static int cx23885_dev_setup(struct cx23885_dev *dev)
    lines];
    cx23885_vbi_fmt.capabilities = V4L2_CAP_SLICED_VBI_CAPTURE;
    }
    dev->vdev = cx23885_vdev_init(dev, &dev->pci->dev,
                &cx23885_video_template, dev->name);
+   if (!dev->vdev) {
+       ret = -ENOMEM;
+       goto fail_unreg_dev_6;

With this change in place, the Linux kernel is now protected from the vulnerability associated with CVE-2023-52918. It is highly recommended to update your systems with the latest kernel updates containing the patch for this vulnerability. You can find the full kernel commit patch for this fix here.

In conclusion, we have seen how a seemingly small oversight in the 'media: pci: cx23885' component of the Linux kernel has led to a potential vulnerability that could result in system crashes. Thankfully, the issue was detected, and a fix has been implemented to ensure that NULL pointer checks are properly conducted - thereby mitigating the risk associated with CVE-2023-52918.

Make sure to follow this space for more updates on Linux kernel vulnerabilities and resolutions to keep your systems safe and secure!

Timeline

Published on: 10/22/2024 08:15:02 UTC
Last modified on: 10/24/2024 03:55:26 UTC