Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

i3c: mipi-i3c-hci: Fix race in DMA ring dequeue

The HCI DMA dequeue path (hci_dma_dequeue_xfer()) may be invoked for multiple transfers that timeout around the same time. However, the function is not serialized and can race with itself.

When a timeout occurs, hci_dma_dequeue_xfer() stops the ring, processes incomplete transfers, and then restarts the ring. If another timeout triggers a parallel call into the same function, the two instances may interfere with each other - stopping or restarting the ring at unexpected times.

Add a mutex so that hci_dma_dequeue_xfer() is serialized with respect to itself.