CVE-2023-52607 in Linux
Summary
by MITRE • 03/06/2024
In the Linux kernel, the following vulnerability has been resolved:
powerpc/mm: Fix null-pointer dereference in pgtable_cache_add
kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure. Ensure the allocation was successful by checking the pointer validity.
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Analysis
by VulDB Data Team • 05/21/2025
The vulnerability identified as CVE-2023-52607 represents a critical null-pointer dereference flaw within the Linux kernel's powerpc architecture memory management subsystem. This issue specifically affects the pgtable_cache_add function where the kasprintf() kernel function is employed to dynamically allocate memory for string formatting operations. The flaw arises from inadequate error handling when the memory allocation process fails, creating a scenario where the kernel attempts to dereference a null pointer during memory management operations. Such conditions can occur when the system experiences memory pressure or allocation failures during normal operation, particularly in embedded systems or virtualized environments running powerpc-based architectures.
The technical implementation of this vulnerability stems from the kernel's failure to validate the return value of kasprintf() before proceeding with subsequent operations. The kasprintf() function, which is part of the kernel's string formatting utilities, allocates memory for formatted strings and returns a pointer to this allocated memory. When memory allocation fails, kasprintf() returns NULL, but the vulnerable code does not check for this condition before attempting to use the returned pointer. This pattern violates fundamental kernel security principles and creates a potential crash condition that can be exploited to cause system instability or denial of service attacks. The vulnerability directly maps to CWE-476 which describes the weakness of null pointer dereference in software implementations.
The operational impact of CVE-2023-52607 extends beyond simple system crashes, as it can be leveraged to create persistent denial of service conditions within powerpc-based systems. Attackers with local access or those capable of triggering specific memory allocation scenarios could potentially exploit this vulnerability to force kernel panics or system reboots, disrupting critical operations in embedded systems, network infrastructure, or virtualized environments. The vulnerability is particularly concerning in mission-critical applications where system stability is paramount, as it can be triggered through normal kernel memory management operations without requiring special privileges. The flaw affects systems running Linux kernel versions prior to the fix, particularly those utilizing powerpc architecture with memory management subsystems that rely on pgtable_cache_add functionality.
Mitigation strategies for CVE-2023-52607 require immediate patch application to the affected Linux kernel versions, as the fix involves implementing proper null pointer validation after kasprintf() calls within the pgtable_cache_add function. System administrators should prioritize updating kernel versions to those containing the patched implementation, which typically includes the necessary validation checks to ensure memory allocation success before pointer usage. Additionally, monitoring systems should be implemented to detect potential exploitation attempts through anomalous memory allocation patterns or kernel panic events. The fix aligns with ATT&CK technique T1499.004 which covers network denial of service attacks, as the vulnerability can be used to create system instability. Organizations should also consider implementing memory allocation monitoring and resource management policies to reduce the likelihood of triggering allocation failures that could expose this vulnerability. The remediation process should include comprehensive testing of patched kernels in production environments to ensure compatibility and stability across all powerpc-based systems.