bhyve vulnerabilities

In bhyve's framebuffer device model, maximum resolution constants were duplicated between the framebuffer and RFB modules and got out of sync. Additionally, writes to the framebuffer BAR could set arbitrary width and height values without validation, and the framebuffer BAR I/O and RFB rendering threads were not synchronized.

In bhyve's HDA audio device model, zero-length Buffer Descriptor List (BDL) entries were not checked when starting a stream. A zero-length entry caused an out-of-bounds read or write during DMA transfer processing. BDL fields could also be modified by the guest after validation.

In bhyve's xHCI (USB 3) device model, the event ring size provided by the guest was not validated or saved. The size was re-read from guest memory on each use, and Transfer Request Block (TRB) fields were loaded without protection against concurrent modification by the guest. This race condition could be triggered by a guest running malicious, privileged code.