CVE-2022-49739 is a vulnerability identified in the Linux kernel's GFS2 (Global File System 2) component, specifically related to the handling of inline (stuffed) inodes. Inodes are data structures used to represent filesystem objects, and stuffed inodes are stored directly within the inode structure to optimize small files. The vulnerability arises because the Linux kernel did not properly validate the size of these inline inodes when reading them from disk via the gfs2_dinode_in() function. Prior to the fix, the kernel relied on truncating inline data to a maximum allowed size in the functions stuffed_readpage() and gfs2_unstuffer_page(), which was insufficient to prevent on-disk corruption. This improper validation could allow malformed or corrupted inode data to be processed, potentially leading to filesystem corruption or instability. The patch removes the ineffective truncation checks and introduces a strict size validation to ensure that the inode size of stuffed inodes falls within an allowed range, thereby preventing the possibility of on-disk corruption caused by malformed inodes. This vulnerability is rooted in the kernel's filesystem code and affects all Linux systems using GFS2 filesystems with the vulnerable kernel versions. No known exploits are currently reported in the wild, and the vulnerability does not have an assigned CVSS score yet.

For European organizations, the impact of CVE-2022-49739 primarily concerns systems utilizing the GFS2 filesystem on Linux kernels with the vulnerable code. GFS2 is commonly used in clustered environments and enterprise storage solutions, including those in data centers and cloud infrastructures. Exploitation could lead to filesystem corruption, resulting in data loss, system crashes, or degraded availability of critical services. This can disrupt business operations, especially for organizations relying on high-availability clusters or shared storage. Although no active exploits are known, the risk remains for targeted attacks or accidental data corruption. The vulnerability could also complicate incident response and recovery efforts if filesystem integrity is compromised. Confidentiality impact is limited since this is a filesystem integrity issue rather than a direct data disclosure vulnerability. However, integrity and availability impacts are significant, particularly for organizations with critical data stored on GFS2 volumes. European organizations with large-scale Linux deployments in sectors such as finance, telecommunications, government, and cloud service providers are particularly at risk due to their reliance on robust storage solutions.

Organizations should immediately verify if their Linux systems use the GFS2 filesystem and identify the kernel versions in use. Applying the official Linux kernel patches that address CVE-2022-49739 is the primary mitigation step. Since the vulnerability involves kernel-level filesystem code, updating to a patched kernel version is essential. For environments where immediate patching is challenging, organizations should consider temporarily limiting access to affected systems, especially restricting untrusted users from writing to GFS2 volumes. Regular backups and filesystem integrity checks should be conducted to detect and recover from any corruption. Additionally, monitoring system logs for unusual filesystem errors or kernel warnings related to GFS2 can help detect potential exploitation attempts or corruption events. Organizations should also review cluster and storage configurations to ensure that only trusted nodes have write access to shared GFS2 filesystems. Finally, coordinate with Linux distribution vendors for timely security updates and guidance specific to their kernel packages.