The Linux kernel contains an out of bounds access vulnerability in the Squashfs filesystem driver that could lead to information disclosure or system instability.

This flaw exists in the squashfs_copy_data function, where a negative offset read from a crafted Squashfs filesystem results in an out of bounds memory access. While mounting the filesystem requires administrative privileges, an unprivileged user can trigger the vulnerability by reading a crafted file after the filesystem is mounted.

This vulnerability poses a risk to system integrity and data confidentiality. An attacker who can successfully exploit this flaw may be able to read sensitive kernel memory or cause a system crash, resulting in potential service denial. Although the CVSS score of 7.1 indicates a high severity, the requirement for an already mounted, malicious Squashfs filesystem limits the immediate attack surface in standard production environments.

Immediate Action: Apply the latest kernel security updates provided by your distribution vendor, specifically ensuring the kernel is updated to version 5.10.270, 5.15.221, 6.1.188, 6.6.157, or later.

Proactive Monitoring: Review system logs for kernel oops or segmentation faults that may indicate attempts to trigger memory corruption errors.

Compensating Controls: Restrict the ability of unprivileged users to mount removable media or arbitrary filesystem images to prevent the introduction of malicious Squashfs filesystems.

Public Exploit Available: Unknown

Given the potential for kernel level memory corruption, this vulnerability should be prioritized for patching during the next scheduled maintenance cycle. System administrators should verify their kernel versions against the provided fixed releases and prioritize updates for systems that frequently handle external or untrusted filesystem images.