CVE-2021-47064: 
Linux Kernel vulnerability analysis and mitigation

In the Linux kernel, a vulnerability has been identified and assigned CVE-2021-47064. The issue affects the mt76 driver and involves a potential DMA mapping leak. The vulnerability occurs when the 'buf' variable is uninitialized in mt76_dma_tx_queue_skb_raw, causing its field skip_unmap to potentially inherit a non-zero value from stack garbage. This could result in DMA mappings for MCU command frames not being unmapped after completion (Kernel Git).

The vulnerability stems from an uninitialized struct mt76_queue_buf variable named 'buf' in the mt76_dma_tx_queue_skb_raw function. When this structure is not properly initialized, its skip_unmap field could contain random values from stack memory. If this field inherits a non-zero value, it prevents the proper unmapping of DMA mappings for MCU command frames after their completion (Kernel Git). The issue has been assigned a CVSS v3.1 base score of 5.3 (Medium) with vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L (NVD).

The vulnerability can lead to DMA mapping leaks in the Linux kernel's mt76 wireless driver. This could potentially result in resource leaks and memory management issues in the affected system (NVD).

The vulnerability requires no user interaction and can be triggered through the normal operation of the mt76 wireless driver when handling MCU command frames (NVD).

The issue has been fixed by properly initializing the buf structure using 'struct mt76_queue_buf buf = {};' in the mt76_dma_tx_queue_skb_raw function. The fix has been implemented in the Linux kernel (Kernel Git).