CVE-2024-46826 in Linux
Summary
by MITRE • 09/27/2024
In the Linux kernel, the following vulnerability has been resolved:
ELF: fix kernel.randomize_va_space double read
ELF loader uses "randomize_va_space" twice. It is sysctl and can change at any moment, so 2 loads could see 2 different values in theory with unpredictable consequences.
Issue exactly one load for consistent value across one exec.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/04/2026
The vulnerability CVE-2024-46826 represents a critical race condition within the Linux kernel's ELF loader implementation that directly impacts memory layout randomization mechanisms. This flaw specifically targets the kernel.randomize_va_space parameter which controls address space layout randomization, a fundamental security feature designed to prevent exploitation of memory corruption vulnerabilities through techniques like return-oriented programming and data injection attacks. The vulnerability arises from the improper handling of this critical system parameter during the ELF loading process where the kernel performs two separate reads of the randomize_va_space value without ensuring consistency between these operations.
The technical implementation flaw stems from the kernel's ELF loader executing the randomize_va_space parameter check twice during a single execution operation, creating a window where the parameter value could change between these two reads. This parameter controls the level of address space randomization applied to processes, with values typically ranging from 0 (no randomization) to 2 (full randomization including heap and stack). When the system parameter changes between these two reads, the kernel may apply inconsistent memory layout randomization strategies to the same executable, potentially creating predictable memory layouts that adversaries could exploit. This race condition directly violates the principle of atomicity in security-critical operations and creates a potential attack surface where memory layout predictions become possible.
The operational impact of this vulnerability extends beyond simple memory layout inconsistencies, as it fundamentally undermines the effectiveness of kernel-based security mitigations that rely on consistent randomization behavior. Attackers could potentially exploit this inconsistency to bypass security controls such as stack canaries, memory protection mechanisms, and other exploit mitigation techniques. The vulnerability is particularly concerning because it operates at the kernel level where the consequences of inconsistent security behavior can be catastrophic, potentially allowing for privilege escalation or information disclosure attacks. The unpredictable nature of the vulnerability means that exploitation techniques could vary based on timing conditions and system load, making detection and prevention particularly challenging.
Mitigation strategies for CVE-2024-46826 focus on ensuring atomic access to the randomize_va_space parameter during ELF loading operations. The fix implemented in the kernel ensures that the randomize_va_space value is read exactly once per execution operation, maintaining consistency throughout the entire loading process. This approach aligns with security best practices outlined in the CWE taxonomy under CWE-362, which addresses race conditions in security-critical operations. Organizations should prioritize applying the kernel patches that resolve this vulnerability, particularly in environments where memory layout randomization is critical for security. The remediation process should include comprehensive testing to ensure that the fix does not introduce performance regressions or compatibility issues with existing applications. System administrators should also monitor for any unusual patterns in system behavior that might indicate exploitation attempts, as the vulnerability's impact on security mechanisms makes it a high-priority target for advanced persistent threats.