CVE-2018-10322 in Linux
Summary
by MITRE
The xfs_dinode_verify function in fs/xfs/libxfs/xfs_inode_buf.c in the Linux kernel through 4.16.3 allows local users to cause a denial of service (xfs_ilock_attr_map_shared invalid pointer dereference) via a crafted xfs image.
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Analysis
by VulDB Data Team • 03/07/2023
The vulnerability identified as CVE-2018-10322 resides within the Linux kernel's XFS filesystem implementation, specifically in the xfs_dinode_verify function located in fs/xfs/libxfs/xfs_inode_buf.c. This flaw represents a critical denial of service vulnerability that can be exploited by local users through manipulation of crafted XFS image files. The vulnerability manifests when the kernel processes malformed XFS filesystem structures, leading to an invalid pointer dereference that ultimately results in system instability and potential system crashes.
The technical root cause of this vulnerability stems from inadequate input validation within the xfs_dinode_verify function which is responsible for verifying the integrity of XFS inode buffers. When processing a specially crafted XFS image, the function fails to properly validate the inode data structure before attempting to access certain memory locations. This validation failure creates a scenario where xfs_ilock_attr_map_shared is called with an invalid pointer reference, leading to a kernel panic and system denial of service. The vulnerability operates at the kernel level, making it particularly dangerous as it can compromise the entire system's stability and availability.
The operational impact of this vulnerability extends beyond simple system crashes, as local users with access to the system can leverage this weakness to disrupt normal operations and potentially cause extended downtime. Since the vulnerability is exploitable locally, it can be particularly problematic in multi-tenant environments where users might attempt to destabilize the system or in scenarios where system administrators need to maintain high availability. The flaw affects Linux kernel versions through 4.16.3, representing a substantial attack surface given the widespread adoption of these kernel versions in enterprise and cloud environments. This vulnerability can be classified under CWE-476 as a NULL pointer dereference, and from an ATT&CK perspective, it maps to T1499.004 for network denial of service and T1068 for local privilege escalation opportunities.
Mitigation strategies for CVE-2018-10322 primarily involve applying the appropriate kernel security patches released by the Linux kernel community. System administrators should immediately update to kernel versions 4.16.4 or later where this vulnerability has been addressed through enhanced input validation in the xfs_dinode_verify function. Additionally, implementing proper filesystem access controls and limiting local user privileges can reduce the attack surface. Organizations should also consider monitoring for suspicious XFS image file operations and implementing automated patch management systems to ensure timely deployment of security fixes. The vulnerability highlights the importance of robust input validation in kernel space code and demonstrates how seemingly minor validation gaps can lead to severe system stability issues.