CVE-2022-48657 in Linux
Summary
by MITRE • 04/28/2024
In the Linux kernel, the following vulnerability has been resolved:
arm64: topology: fix possible overflow in amu_fie_setup()
cpufreq_get_hw_max_freq() returns max frequency in kHz as *unsigned int*, while freq_inv_set_max_ratio() gets passed this frequency in Hz as 'u64'. Multiplying max frequency by 1000 can potentially result in overflow -- multiplying by 1000ULL instead should avoid that...
Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool.
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Analysis
by VulDB Data Team • 05/30/2024
The vulnerability identified as CVE-2022-48657 resides within the Linux kernel's arm64 architecture implementation, specifically in the topology subsystem where the amu_fie_setup() function processes frequency-related operations. This issue demonstrates a critical type conversion and arithmetic overflow problem that could potentially compromise system stability and security. The flaw occurs during the handling of CPU frequency management operations where hardware maximum frequencies are processed through multiple function calls with different data type expectations.
The technical root cause stems from a fundamental mismatch between data types used in frequency calculations. The cpufreq_get_hw_max_freq() function returns maximum frequency values expressed as unsigned integers in kilohertz units, while the subsequent freq_inv_set_max_ratio() function expects this frequency value in hertz and accepts it as a u64 data type. When the system attempts to convert from kHz to Hz by multiplying by 1000, the operation can exceed the maximum representable value for the target data type, leading to integer overflow conditions that may result in unpredictable behavior or system instability.
This vulnerability falls under the CWE-191 Integer Underflow/Overflow category, specifically representing an unsigned integer overflow condition where arithmetic operations exceed the maximum value that can be represented. The issue is particularly concerning in embedded systems and server environments where precise frequency management is critical for performance optimization and power efficiency. The vulnerability was discovered through static analysis conducted by the Linux Verification Center using the SVACE tool, highlighting the importance of comprehensive code analysis in identifying subtle but potentially dangerous integer arithmetic issues.
The operational impact of this vulnerability extends beyond simple system instability, potentially affecting system responsiveness and resource management capabilities within arm64-based systems. When overflow conditions occur during frequency calculations, the system may miscalculate performance parameters, leading to incorrect CPU governor behavior and potentially compromising the overall system performance. Attackers could theoretically exploit this condition to cause denial of service scenarios or potentially manipulate system resources in ways that affect security-sensitive operations. The vulnerability affects systems running Linux kernels with arm64 architecture where the AMU (Advanced Main Unit) functionality is utilized, particularly in server and embedded systems.
Mitigation strategies should focus on updating to kernel versions that contain the patched implementation, which resolves the issue by using 1000ULL instead of 1000 in the multiplication operation to ensure proper handling of the data type conversion. System administrators should also implement monitoring solutions to detect potential overflow conditions and verify that all arm64-based systems are running patched kernel versions. The fix addresses the underlying arithmetic overflow by ensuring proper unsigned long long integer handling during the frequency conversion process, aligning with the ATT&CK framework's defense evasion techniques by preventing potential exploitation through system instability. Organizations should prioritize patching this vulnerability as part of their regular security maintenance protocols to maintain system integrity and prevent potential exploitation scenarios that could affect system availability and performance.