CVE-2010-2653 in Linux
Summary
by MITRE
Race condition in the hvc_close function in drivers/char/hvc_console.c in the Linux kernel before 2.6.34 allows local users to cause a denial of service or possibly have unspecified other impact by closing a Hypervisor Virtual Console device, related to the hvc_open and hvc_remove functions.
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Analysis
by VulDB Data Team • 09/26/2021
The vulnerability described in CVE-2010-2653 represents a critical race condition within the Linux kernel's Hypervisor Virtual Console (hvc) subsystem, specifically affecting versions prior to 2.6.34. This flaw exists in the hvc_close function located in drivers/char/hvc_console.c, where improper synchronization between concurrent operations creates a window of opportunity for malicious exploitation. The race condition manifests when multiple threads attempt to access or modify the same hvc device structure simultaneously during the close operation, leading to unpredictable system behavior and potential security implications.
The technical implementation of this vulnerability stems from inadequate locking mechanisms within the hvc subsystem, which fails to properly serialize access to shared data structures during device lifecycle operations. When hvc_close executes in conjunction with hvc_open and hvc_remove functions, the lack of proper mutual exclusion leads to a scenario where the device structure may be accessed or modified by multiple processes concurrently. This condition is particularly dangerous because it can result in memory corruption, null pointer dereferences, or inconsistent device state management. The flaw operates at the kernel level, making it particularly severe as it can be exploited by local users with minimal privileges to disrupt system operations or potentially escalate their privileges through memory corruption techniques.
The operational impact of this vulnerability extends beyond simple denial of service, as demonstrated by the unspecified other impacts mentioned in the CVE description. Local attackers can leverage this race condition to cause system instability, leading to kernel panics, system crashes, or unpredictable behavior in hypervisor environments where hvc devices are actively used. In virtualized environments, this vulnerability could be particularly damaging as it may compromise the stability of multiple guest operating systems running on the same hypervisor host. The race condition also creates opportunities for privilege escalation attacks, as the inconsistent state management during device closure may allow attackers to manipulate kernel memory structures or bypass security controls. This vulnerability directly relates to CWE-362, which describes race conditions in concurrent programming scenarios, and aligns with ATT&CK technique T1068, which covers privilege escalation through kernel exploits.
Mitigation strategies for CVE-2010-2653 require immediate kernel version upgrades to 2.6.34 or later, where the race condition has been addressed through proper locking mechanisms and synchronization primitives. System administrators should implement comprehensive patch management procedures to ensure all affected systems are updated promptly, particularly in virtualized environments where hvc devices are prevalent. Additionally, monitoring systems should be configured to detect unusual patterns in device closure operations or kernel panic events that may indicate exploitation attempts. The fix implemented in the patched kernel versions involves introducing proper mutex locking around the device structure access during close operations, ensuring that hvc_close executes atomically with respect to hvc_open and hvc_remove functions. Organizations should also consider implementing runtime protections such as kernel address space layout randomization and stack canaries to further reduce the attack surface and mitigate potential exploitation attempts.