Linux Kernel Link DMA Release Vulnerability in ASoC SOF Intel HDA-DAI

A vulnerability in the Linux kernel's ASoC SOF Intel HDA-DAI component allows for improper management of link DMA channels. When a stream is stopped, the link DMA should not be released, as this can create a window for other streams to interfere and 'steal' the link DMA, leading to mixed-up channels. This mismanagement can cause firmware errors or crashes. While the issue is not commonly reproducible under normal conditions, it can occur if another stream is initiated between the stop and restart of a stream, mixing up the link DMA channels and causing errors.

Impact

Exploitation of this vulnerability can result in a firmware error or crash due to mixed-up link DMA channels, causing improper stream management and potential interference between audio streams.

Reproduction

To reproduce this vulnerability, first play a stream on one audio channel using the 'aplay' command, then interrupt this stream with 'CTRL+z' before it finishes. While the first stream is paused, start a second stream on a different channel. This will cause the link DMA channels to mix up, leading to a firmware error or crash.