radare2: Infinite relocation-chain loop causes denial of service in radare2 NE parser

radare2 is a UNIX-like reverse engineering framework and command-line toolset. Prior to 6.2.0, radare2's NE relocation fixup-chain parser was vulnerable because the NE relocation parser followed fixup chains without an active iteration limit or cycle detection. The vulnerability is triggered by opening a crafted NE executable whose in-bounds relocation entry points back to itself instead of reaching 0xffff. The parser repeatedly processed the same relocation and allocated another relocation object on each iteration. This can cause denial of service through continuous CPU and memory consumption. This issue is fixed in version 6.2.0.