CVE-2026-93170

Overview

A race condition in the Xilinx AXI DMA and MCDMA interrupt handlers can cause a DMA channel to be marked idle prematurely, leading to spurious transfer attempts and possible descriptor corruption or missed completions. The flaw is limited to the Linux kernel’s Xilinx DMA driver.

Description

In the Linux kernel, the following vulnerability has been resolved: dmaengine: xilinx_dma: Fix channel idle state management in AXIDMA and MCDMA interrupt handlers Fix a race condition in AXIDMA and MCDMA irq handlers where the channel could be incorrectly marked as idle and attempt spurious transfers when descriptors are still being processed. The issue occurs when: 1. Multiple descriptors are queued and active. 2. An interrupt fires after completing some descriptors. 3. xilinx_dma_complete_descriptor() moves completed descriptors to done_list. 4. Channel is marked idle and start_transfer() is called even though active_list still contains unprocessed descriptors. 5. This leads to premature transfer attempts and potential descriptor corruption or missed completions. Only mark the channel as idle and start new transfers when the active list is actually empty, ensuring proper channel state management and avoiding spurious transfer attempts.

Impact

{'confidentiality': 'No direct impact', 'integrity': 'Potential corruption of DMA descriptors and loss of data integrity for DMA transfers', 'availability': 'Possible denial‑of‑service for DMA operations if repeated spurious transfers exhaust resources or cause kernel instability'}

Remediation

['Upgrade the Linux kernel to a version that includes the Xilinx DMA driver patch (check vendor release notes for the specific commit or patch ID).', 'If a kernel update is not immediately possible, disable or restrict the use of Xilinx DMA channels that are not required for critical operations.', 'Apply any vendor‑supplied firmware or driver updates for Xilinx devices that address DMA channel state management.', 'Monitor system logs for DMA interrupt errors or descriptor corruption events and verify that the kernel no longer reports the race condition.', 'Consider enabling kernel debugging options (e.g., CONFIG_DEBUG_DMA) to detect anomalous DMA activity during testing.']

Risk context

The vulnerability has a medium CVSS v3 score of 4.7 and no EPSS data is available. It poses a moderate risk primarily to data integrity and availability of DMA operations in systems using Xilinx DMA drivers.

Affected products

• Linux kernel
• Xilinx AXI DMA
• Xilinx MCDMA
• Xilinx SoC
• Xilinx FPGA
• Xilinx SDSoC
• Xilinx Vivado
• Xilinx SDK