In nbd-server in nbd before 3.24, there is an integer overflow with a resultant heap-based buffer overflow. A value of 0xffffffff in the name length field will cause a zero-sized buffer to be allocated for the name, resulting in a write to a dangling pointer. This issue exists for the NBD_OPT_INFO, NBD_OPT_GO, and NBD_OPT_EXPORT_NAME messages.