The framebuffer device model's maximum resolution constants were duplicated between the framebuffer and RFB modules and had gotten 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.
A malicious guest can crash the bhyve process or potentially execute arbitrary code in the host userspace context running the virtual machine, subject to bhyve's Capsicum sandbox.
The HDA audio device model did not check for zero-length Buffer Descriptor List (BDL) entries when starting a stream. A zero-length entry caused an out-of-bounds read or write during DMA transfer processing. BDL fields were also subject to modification by the guest after validation.
A malicious guest can crash the bhyve process or potentially execute arbitrary code in the host userspace context running the virtual machine, subject to bhyve's Capsicum sandbox.
The xHCI (USB 3) device model did not validate or save the event ring size provided by the guest. 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.
A malicious guest can crash the bhyve process or potentially execute arbitrary code in the host userspace context running the virtual machine, subject to bhyve's Capsicum sandbox.