CVE-2026-74419 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Adjust size for copy_to_user()
The amount of data returned to user space should be limited by the buffer size provided by the application. If the buffer is smaller than the data size, return only the portion that fits instead of failing.
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Analysis
by VulDB Data Team • 08/15/2026
This vulnerability exists in the amdxdna driver within the Linux kernel's acceleration subsystem where improper handling of buffer size constraints during data transfer operations creates a potential security risk. The flaw specifically affects the copy_to_user function implementation which is responsible for transferring data from kernel space back to user space applications. When an application provides a buffer that is smaller than the amount of data the driver intends to return, the system should gracefully truncate the data to fit within the available buffer space rather than failing the operation entirely.
The technical nature of this vulnerability stems from inadequate bounds checking and size validation mechanisms within the kernel driver's data transfer logic. According to common weakness enumeration standards, this represents a classic buffer overflow prevention issue where proper input sanitization fails to occur during kernel-space data handling operations. The vulnerability manifests when applications make requests that exceed their allocated buffer boundaries, creating conditions where the driver might either attempt to write beyond memory limits or fail to properly handle the partial data transfer scenario.
From an operational perspective, this vulnerability could enable malicious actors to exploit inconsistent behavior in the amdxdna driver through carefully crafted application inputs. While the specific attack vector may not be immediately obvious, it represents a potential avenue for denial of service conditions where legitimate applications might experience unexpected termination or data truncation. The impact extends beyond simple functionality issues as improper error handling in kernel space can potentially lead to system instability or information disclosure scenarios.
The mitigation approach requires implementing proper size validation before any copy_to_user operations are executed within the driver code. This involves verifying that the amount of data to be transferred does not exceed the user-provided buffer capacity and adjusting the transfer size accordingly. The solution aligns with established security practices for kernel development where all data transfers must be bounded and validated against provided buffer limits. Organizations should ensure their kernel versions include patches addressing this specific vulnerability, particularly in environments utilizing AMD XDNA acceleration hardware. Regular kernel updates and proper security hardening measures remain essential for maintaining system integrity.
This vulnerability demonstrates the critical importance of robust input validation in kernel-space operations as outlined in various security frameworks including those referenced by the attack technique numbering system. Proper implementation of buffer size constraints prevents potential escalation paths while maintaining application compatibility through graceful degradation when resource limitations are encountered. The fix ensures that applications receive only the data they can properly handle rather than experiencing abrupt failures or undefined behavior during legitimate operations.