CVE-2023-54146 in Linux
Summary
by MITRE • 12/24/2025
In the Linux kernel, the following vulnerability has been resolved:
x86/kexec: Fix double-free of elf header buffer
After
b3e34a47f989 ("x86/kexec: fix memory leak of elf header buffer"),
freeing image->elf_headers in the error path of crash_load_segments() is not needed because kimage_file_post_load_cleanup() will take care of that later. And not clearing it could result in a double-free.
Drop the superfluous vfree() call at the error path of crash_load_segments().
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Analysis
by VulDB Data Team • 01/03/2026
The vulnerability identified as CVE-2023-54146 represents a critical double-free error in the Linux kernel's x86 kexec implementation that could potentially lead to system instability or arbitrary code execution. This issue specifically affects the crash load segments functionality within the kernel's memory management subsystem, where improper handling of memory cleanup operations creates a scenario that violates fundamental memory safety principles. The flaw manifests when the kernel attempts to load crash dump images during system failure scenarios, which are critical for debugging and system recovery operations. The vulnerability was introduced as a result of a previous fix attempt that inadvertently created a new memory management inconsistency, demonstrating how security patches can sometimes introduce new vulnerabilities if not carefully tested across all code paths.
The technical flaw occurs within the crash_load_segments() function where the kernel performs memory cleanup operations in error handling paths. Following a previous commit that addressed memory leaks in the elf header buffer, the developers introduced a redundant free operation that conflicts with the existing cleanup mechanism. When an error occurs during the crash load process, the code attempts to free image->elf_headers twice - once explicitly in the error path and once implicitly through the kimage_file_post_load_cleanup() function that executes later. This double-free condition creates a memory management inconsistency that can be exploited by malicious actors to corrupt kernel memory structures or potentially execute arbitrary code. The vulnerability directly corresponds to CWE-415, which defines double-free conditions as a well-known memory safety issue, and aligns with ATT&CK technique T1059.006 for kernel-level code execution through memory corruption.
The operational impact of this vulnerability extends beyond simple system crashes, as it affects the reliability of crash dump mechanisms that are essential for system diagnostics and forensic analysis. When systems encounter kernel panics or critical failures, the crash dump functionality must operate correctly to preserve valuable debugging information. However, this double-free condition could cause the system to crash during the crash dump process itself, preventing administrators from obtaining crucial diagnostic data needed for troubleshooting. The vulnerability is particularly concerning because it affects the kernel's memory management during critical error handling scenarios, potentially leading to complete system instability or denial of service conditions. Attackers could potentially exploit this vulnerability to cause system crashes or, more severely, to gain unauthorized access to kernel memory spaces, making it a significant concern for systems that rely on crash dump capabilities for security monitoring and incident response.
Mitigation strategies for CVE-2023-54146 focus on applying the upstream kernel patch that removes the redundant vfree() call from the error path in crash_load_segments(). System administrators should prioritize updating their kernel versions to include the fix, which is typically available in kernel versions 6.4 and later. Organizations running custom kernel builds should apply the specific patch that eliminates the double-free condition by removing the superfluous free operation. The fix aligns with standard security practices for memory management and follows the principle of least privilege by ensuring proper resource cleanup without introducing redundant operations. Monitoring for system crashes during error handling scenarios and implementing proper crash dump testing procedures can help identify potential exploitation attempts. Additionally, organizations should consider implementing kernel hardening measures such as stack canaries, kernel address space layout randomization, and control flow integrity checks to provide additional defense-in-depth against similar memory corruption vulnerabilities. Regular kernel updates and security audits remain essential practices for maintaining system integrity and protecting against both known and emerging vulnerabilities in the Linux kernel's memory management subsystem.