CVE-2023-53217: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53217 is a vulnerability in the Linux kernel related to the nubus subsystem, discovered and disclosed on September 15, 2025. The issue stems from an incorrect conversion to proccreatesingle_data() in the nubus code, affecting systems with the nubus subsystem enabled (NVD).

The vulnerability manifests when reading files in /proc/bus/nubus, resulting in a segmentation fault. The root cause is that the proccreatesingledata() conversion is not equivalent to the original code, specifically in the context of singleopen(file, nubusprocrsrcshow, PDEDATA(inode)). This leads to a data read fault at address 0x00000020, triggering a kernel oops (Ubuntu).

When exploited, the vulnerability causes a kernel segmentation fault and system crash when attempting to read files from the /proc/bus/nubus directory, potentially leading to denial of service conditions (NVD).

Multiple Linux distributions have released patches to address this vulnerability. Ubuntu has fixed the issue in version 5.15.0-86.96 for Ubuntu 22.04 LTS, version 5.15.0-86.95~20.04.1 for Ubuntu 20.04 LTS with HWE kernel, and various other kernel variants (Ubuntu).