CVE-2010-2798 in Linux
Summary
by MITRE
The gfs2_dirent_find_space function in fs/gfs2/dir.c in the Linux kernel before 2.6.35 uses an incorrect size value in calculations associated with sentinel directory entries, which allows local users to cause a denial of service (NULL pointer dereference and panic) and possibly have unspecified other impact by renaming a file in a GFS2 filesystem, related to the gfs2_rename function in fs/gfs2/ops_inode.c.
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Analysis
by VulDB Data Team • 12/29/2024
The vulnerability described in CVE-2010-2798 represents a critical flaw in the Linux kernel's implementation of the Global File System 2 (GFS2) filesystem driver. This issue resides within the gfs2_dirent_find_space function located in fs/gfs2/dir.c, where an incorrect size value is utilized during calculations involving sentinel directory entries. The flaw specifically manifests when a file is renamed within a GFS2 filesystem, triggering a cascade of errors that can lead to system instability and potential denial of service conditions. The vulnerability affects all Linux kernel versions prior to 2.6.35, making it a significant concern for systems running older kernel versions.
The technical implementation of this vulnerability stems from improper handling of directory entry size calculations within the GFS2 filesystem's directory management routines. When the gfs2_rename function processes file renaming operations, it relies on the gfs2_dirent_find_space function to locate appropriate space for directory entries. However, due to the incorrect size value being used in these calculations, the system attempts to manipulate directory structures in ways that result in invalid memory references. This incorrect sizing leads to a NULL pointer dereference condition that ultimately causes the kernel to panic and crash the entire system.
The operational impact of this vulnerability extends beyond simple denial of service, as it represents a potential vector for system compromise and data availability disruption. Local users with access to a GFS2 filesystem can exploit this vulnerability to cause system crashes, effectively rendering the affected system unusable until manual reboot occurs. The potential for unspecified other impacts suggests that this flaw could potentially be leveraged for more sophisticated attacks, particularly given that it operates at the kernel level where privilege escalation opportunities often exist. This vulnerability directly aligns with CWE-125: Out-of-bounds Read, as the incorrect size calculations lead to memory access violations that can trigger kernel panic conditions.
From a security perspective, this vulnerability demonstrates the critical importance of proper input validation and memory management in kernel space code. The flaw exists in the core filesystem operations that handle directory manipulation, making it particularly dangerous as it can be triggered through normal file system operations. The attack vector requires local access to a GFS2 filesystem, but this limitation does not diminish the severity of the impact. System administrators should note that this vulnerability affects enterprise storage environments that rely on GFS2 for shared storage solutions, where a single compromised user account could potentially bring down entire storage clusters. Mitigation strategies should focus on immediate kernel upgrades to version 2.6.35 or later, along with careful monitoring of system stability in environments where GFS2 is actively used.
The vulnerability's relationship to established security frameworks shows clear alignment with ATT&CK techniques related to privilege escalation and system compromise. Specifically, this flaw could potentially be leveraged as part of a broader attack chain where initial access is gained through other vectors, and this vulnerability is then used to escalate privileges or maintain persistence. Organizations using GFS2 filesystems should consider implementing additional monitoring and alerting mechanisms to detect unusual directory manipulation patterns that might indicate exploitation attempts. The remediation process should include comprehensive testing of updated kernel versions in staging environments to ensure compatibility with existing GFS2-based storage solutions before deployment in production systems.