CVE-2022-49451 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_scmi: Fix list protocols enumeration in the base protocol
While enumerating protocols implemented by the SCMI platform using BASE_DISCOVER_LIST_PROTOCOLS, the number of returned protocols is currently validated in an improper way since the check employs a sum between unsigned integers that could overflow and cause the check itself to be silently bypassed if the returned value 'loop_num_ret' is big enough.
Fix the validation avoiding the addition.
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Analysis
by VulDB Data Team • 02/26/2025
The vulnerability identified as CVE-2022-49451 resides within the Linux kernel's firmware subsystem, specifically affecting the ARM System Control and Management Interface (SCMI) driver implementation. This flaw manifests in the base protocol's protocol enumeration mechanism, where the kernel fails to properly validate the number of protocols returned during discovery operations. The issue occurs when the system attempts to enumerate supported protocols through the BASE_DISCOVER_LIST_PROTOCOLS command, which is a fundamental operation for establishing communication with system control platforms that implement SCMI specifications.
The technical root cause of this vulnerability stems from improper integer validation logic within the protocol enumeration code. The flaw involves a critical arithmetic operation where unsigned integers are summed together to validate the number of returned protocols, creating a potential integer overflow condition. When the returned value 'loop_num_ret' exceeds certain thresholds, this arithmetic overflow causes the validation check to be silently bypassed, allowing malformed or malicious protocol enumeration responses to pass through without proper verification. This vulnerability falls under the CWE-191 Integer Underflow/Overflow category, specifically representing an unsigned integer overflow condition that can lead to unexpected program behavior and potential security implications.
The operational impact of this vulnerability extends beyond simple protocol enumeration failures, as it represents a potential pathway for attackers to manipulate the SCMI protocol discovery process. Attackers could potentially exploit this flaw to bypass validation checks during system initialization, potentially allowing unauthorized protocol implementations to be accepted or causing the system to misinterpret legitimate protocol responses. This vulnerability affects systems that rely on ARM-based SCMI implementations for firmware communication and system control, particularly in server and embedded environments where secure protocol enumeration is critical for maintaining system integrity.
The fix for CVE-2022-49451 addresses the core validation issue by eliminating the problematic addition operation that was susceptible to integer overflow. This approach aligns with security best practices for preventing arithmetic overflow conditions in kernel code, ensuring that protocol enumeration validation remains robust against malformed inputs. The mitigation strategy avoids the use of potentially problematic arithmetic operations while maintaining the essential validation functionality needed for secure protocol discovery. This fix directly addresses the ATT&CK technique T1059.005 Command and Scripting Interpreter: Visual Basic, as it prevents unauthorized protocol manipulation that could lead to system compromise through firmware-level attacks. Organizations should apply the kernel patches provided by their respective distributions to address this vulnerability, particularly those systems utilizing ARM-based platforms with SCMI firmware interfaces. The remediation approach follows established kernel security practices for preventing integer overflow conditions in critical system components, ensuring that protocol enumeration operations maintain proper validation boundaries and prevent potential exploitation scenarios.