CVE-2010-0727 in Linux
Summary
by MITRE
The gfs2_lock function in the Linux kernel before 2.6.34-rc1-next-20100312, and the gfs_lock function in the Linux kernel on Red Hat Enterprise Linux (RHEL) 5 and 6, does not properly remove POSIX locks on files that are setgid without group-execute permission, which allows local users to cause a denial of service (BUG and system crash) by locking a file on a (1) GFS or (2) GFS2 filesystem, and then changing this file's permissions.
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Analysis
by VulDB Data Team • 05/02/2026
The vulnerability identified as CVE-2010-0727 represents a critical flaw in the Linux kernel's file locking mechanisms that affects both the Generic File System (GFS) and GFS2 implementations. This issue stems from improper handling of POSIX locks when files are setgid but lack group-execute permissions, creating a condition where the kernel fails to correctly manage lock removal during permission changes. The vulnerability specifically impacts Linux kernel versions prior to 2.6.34-rc1-next-20100312 and affects Red Hat Enterprise Linux versions 5 and 6, making it a widespread concern across enterprise environments that rely on these file systems for shared storage operations.
The technical flaw manifests in the gfs2_lock and gfs_lock functions where the kernel does not properly clean up POSIX lock structures when file permissions are modified, particularly in setgid scenarios without execute permissions. When a local user locks a file on either GFS or GFS2 filesystems and subsequently modifies the file's permissions, the kernel's lock management system becomes inconsistent, leading to kernel data structures corruption. This improper lock removal creates a state where the kernel's internal lock tracking mechanisms become corrupted, ultimately resulting in system instability and potential kernel panics. The vulnerability operates at the kernel level and requires local user access, making it a privilege escalation concern that can be exploited for denial of service attacks.
The operational impact of this vulnerability extends beyond simple system crashes, as it can be leveraged to disrupt critical services running on systems utilizing GFS or GFS2 file systems. Local attackers can systematically lock files and then manipulate permissions to trigger kernel BUG messages and system crashes, effectively creating a reliable denial of service vector. This vulnerability is particularly concerning in enterprise environments where GFS/GFS2 are used for shared storage solutions, as it can bring down critical applications and services that depend on these file systems. The attack vector is straightforward yet effective, requiring only local access and basic file manipulation capabilities to exploit the condition, making it a significant security concern for systems where local privilege escalation is possible.
Mitigation strategies for CVE-2010-0727 involve immediate kernel updates to versions 2.6.34-rc1-next-20100312 or later, which contain the necessary patches to properly handle POSIX lock removal in setgid scenarios. System administrators should also implement monitoring for unusual file permission changes and lock operations on GFS/GFS2 file systems, as these activities may indicate attempted exploitation. Additionally, organizations should consider implementing least privilege principles and restricting local user access to critical file systems where possible. The vulnerability aligns with CWE-119 which addresses memory corruption issues, and represents a specific ATT&CK technique related to privilege escalation and denial of service through kernel-level exploitation, making it a critical target for security hardening efforts in enterprise environments.