CVE-2022-49785 in Linux
Summary
by MITRE • 05/01/2025
In the Linux kernel, the following vulnerability has been resolved:
x86/sgx: Add overflow check in sgx_validate_offset_length()
sgx_validate_offset_length() function verifies "offset" and "length" arguments provided by userspace, but was missing an overflow check on their addition. Add it.
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Analysis
by VulDB Data Team • 11/07/2025
The vulnerability identified as CVE-2022-49785 resides within the Linux kernel's x86 software guard extensions SGX subsystem, specifically in the sgx_validate_offset_length() function that handles validation of memory access parameters. This flaw represents a classic integer overflow vulnerability that could potentially allow malicious userspace processes to bypass memory validation checks and access unauthorized memory regions. The vulnerability is particularly concerning as it affects the Intel SGX (Software Guard Extensions) implementation which provides hardware-based memory encryption and isolation capabilities for sensitive operations. The SGX subsystem is designed to protect data and code from being accessed or modified by processes running at higher privilege levels, making any flaw in its validation logic a significant security concern. The vulnerability manifests when the kernel processes user-supplied offset and length parameters for SGX memory operations without properly validating that their arithmetic addition would not overflow the integer boundaries, potentially leading to memory corruption or unauthorized access patterns.
The technical flaw occurs within the sgx_validate_offset_length() function where user-provided offset and length values are validated for SGX memory operations. The function performs validation checks on individual parameters but fails to implement proper overflow detection when these values are added together to determine memory boundaries. This missing overflow check creates a scenario where an attacker could craft malicious offset and length values such that their sum exceeds the maximum representable value for the integer type used, causing the validation logic to incorrectly accept invalid memory ranges. The vulnerability is classified as a buffer overflow condition that could lead to memory corruption and potentially privilege escalation. This type of flaw aligns with CWE-191 Integer Underflow/Overflow, specifically involving arithmetic overflow during parameter validation. The function operates within the x86 architecture's SGX subsystem, which implements hardware-based memory protection that is critical for maintaining confidentiality and integrity of sensitive computations. The vulnerability exists in the kernel's memory management layer where SGX operations are validated, making it a direct threat to the integrity of the hardware security features.
The operational impact of CVE-2022-49785 extends beyond simple memory corruption as it directly threatens the fundamental security guarantees provided by Intel SGX technology. An attacker who successfully exploits this vulnerability could potentially bypass the memory validation checks that protect SGX enclaves from unauthorized access, allowing for data leakage or code injection attacks against protected memory regions. The implications are particularly severe given that SGX is designed to protect sensitive operations from both kernel-level and user-level attackers, including malicious processes running with elevated privileges. This vulnerability could enable an attacker to access memory that should be protected by SGX, potentially exposing cryptographic keys, sensitive data, or execution contexts that are supposed to remain isolated. The exploitability of this vulnerability is enhanced by the fact that it occurs during parameter validation, meaning that an attacker could manipulate memory access patterns without triggering immediate system failures. The vulnerability affects systems running Linux kernels with SGX support and could be exploited by any process with access to SGX memory operations, potentially compromising the security of applications relying on SGX for protection.
Mitigation strategies for CVE-2022-49785 focus on patching the kernel with the appropriate overflow checks that were introduced to address the specific vulnerability. The fix involves adding proper integer overflow detection when validating the addition of offset and length parameters in the sgx_validate_offset_length() function, ensuring that the arithmetic operation does not exceed the maximum representable value for the integer type used. Organizations should prioritize updating their Linux kernels to versions that include the patched SGX implementation, as this vulnerability directly impacts the security of hardware-based memory protection features. System administrators should also consider monitoring for unusual memory access patterns or SGX-related system calls that might indicate exploitation attempts. The vulnerability's resolution aligns with ATT&CK technique T1059.001 Command and Scripting Interpreter: PowerShell, where the patching process represents a defensive measure against potential exploitation of memory validation flaws. Additionally, security teams should implement comprehensive monitoring of SGX-related kernel operations and consider implementing additional controls around memory access patterns for processes that utilize SGX features. The patch addresses the root cause by ensuring that all parameter combinations are properly validated before being accepted for SGX memory operations, thereby maintaining the integrity of the hardware security boundaries that SGX is designed to enforce.