How to reproduce:
1. Open user's attached project
2. Open "CrashUnity" scene
3. Press play
-- Unity crashes

Reproduced with: 2017.2.0b3, 2017.3.0a5
Not reproduced with: 5.6.3p1, 2017.2.0a4
Regression introduced in 2017.2.0b3

Note: In versions where crash does not occur, exception is thrown:
SocketException: System call failed
System.Net.Sockets.Socket.IOControl (System.Int32 ioControlCode, System.Byte[] optionInValue, System.Byte[] optionOutValue) (at <f044fe2c9e7e4b8e91984b41f0cf0b04>:0)
CrashUnityTm.Start () (at Assets/CrashUnityTm.cs:11)

Stacktrace:

at <unknown> <0xffffffff>
at (wrapper managed-to-native) System.Net.Sockets.Socket.IOControl_internal (intptr,int,byte[],byte[],int&) [0x0000c] in <72f197ac2181426497b3cb5000e39a05>:0
at System.Net.Sockets.Socket.IOControl_internal (System.Net.Sockets.SafeSocketHandle,int,byte[],byte[],int&) [0x00015] in <72f197ac2181426497b3cb5000e39a05>:0
at System.Net.Sockets.Socket.IOControl (int,byte[],byte[]) [0x00024] in <72f197ac2181426497b3cb5000e39a05>:0
at CrashUnityTm.Start () [0x0001f] in /Users/qambp17/Downloads/SocketCrash/Assets/CrashUnityTm.cs:11
at (wrapper runtime-invoke) object.runtime_invoke_void__this__ (object,intptr,intptr,intptr) [0x00020] in <aa1756d827e14afe8f4b9355672b2ab4>:0