HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107, function "pci_vtsock_proc_tx" in "virtio-sock" can lead to to uninitialized memory use. In this situation, there is a check for the return value to be less or equal to "VTSOCK_MAXSEGS", but that check is not sufficient because the function can return "-1" if it finds an error it cannot recover from. Moreover, the negative return value will be used by "iovec_pull" in a while condition that can further lead to more corruption because the function is not designed to handle a negative "iov_len". This issue may lead to a guest crashing the host causing a denial of service and, under certain circumstance, memory corruption. This issue is fixed in commit af5eba2360a7351c08dfd9767d9be863a50ebaba.