CAM (Common Access Method) is a FreeBSD kernel subsystem which handles various aspects of storage device management. Among other responsibilities, it handles device error recovery and can automatically retransmit commands to peripheral devices when a transient error is encountered. When a CAM-managed device responds to a command with an error condition, CAM may automatically retry the command following some error recovery protocol. For instance, it may send a SCSI START UNIT command to the device before retrying the failed command. In this case, an in-memory copy of the original command is preserved for a later retry. However, a specific portion of the command state was not saved correctly, and upon a retry this could lead to memory corruption. The bug can cause kernel panics or other system-level misbehaviour.