CVE-2011-4097 in Linux
Summary
by MITRE
Integer overflow in the oom_badness function in mm/oom_kill.c in the Linux kernel before 3.1.8 on 64-bit platforms allows local users to cause a denial of service (memory consumption or process termination) by using a certain large amount of memory.
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Analysis
by VulDB Data Team • 02/03/2025
The vulnerability identified as CVE-2011-4097 represents a critical integer overflow flaw within the Linux kernel's memory management subsystem, specifically affecting the oom_badness function located in mm/oom_kill.c. This vulnerability exists in kernel versions prior to 3.1.8 and is particularly impactful on 64-bit platforms where the integer overflow can be exploited to manipulate memory allocation decisions. The issue arises from improper handling of large memory values during the out-of-memory (OOM) killer algorithm execution, creating a scenario where legitimate system memory management operations can be disrupted.
The technical flaw manifests when the oom_badness function processes memory usage calculations for processes that are candidates for termination during OOM conditions. Under normal circumstances, this function evaluates process memory consumption to determine which processes should be killed to free system resources. However, when large memory values are processed, the integer overflow causes the calculated badness score to wrap around to a small or negative value, effectively bypassing the intended memory management logic. This overflow condition allows an attacker to manipulate the OOM killer's decision-making process by allocating memory in specific patterns that trigger the overflow.
The operational impact of this vulnerability extends beyond simple denial of service to potentially compromise system stability and availability. Local users can exploit this weakness to either consume excessive memory resources or force the termination of critical system processes through manipulation of the OOM killer's behavior. The vulnerability creates a scenario where a malicious user can cause the system to either waste memory resources by preventing proper process termination or alternatively trigger unintended process killings that could disrupt essential system services. This makes the vulnerability particularly dangerous in multi-user environments or systems where memory resources are constrained.
From a cybersecurity perspective, this vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions, and can be mapped to ATT&CK technique T1499.001 for resource exhaustion attacks. The exploitability of this vulnerability requires local access and knowledge of the kernel's memory management internals, making it a privilege escalation vector rather than a remote attack. However, the impact can be severe as it affects fundamental system stability and can be leveraged to create persistent denial of service conditions that may require system reboot to resolve. The vulnerability demonstrates how seemingly minor integer handling flaws in kernel code can have significant operational consequences, particularly in enterprise environments where system uptime and resource management are critical.
Mitigation strategies for CVE-2011-4097 primarily involve upgrading to Linux kernel versions 3.1.8 or later, where the integer overflow has been properly addressed through improved input validation and boundary checking in the oom_badness function. System administrators should also implement monitoring solutions to detect unusual memory consumption patterns that might indicate exploitation attempts. Additionally, kernel security modules and security frameworks should be configured to limit memory allocation patterns that could trigger the overflow condition. The fix implemented in the patched kernel versions involves strengthening the integer overflow checks within the memory management subsystem to prevent the wraparound conditions that enable the denial of service attacks. Organizations should conduct regular kernel updates and security assessments to ensure protection against similar vulnerabilities in their Linux-based systems.