www.sandboxie.com :: View topic - minor: some norelocs DLLs cannot be loaded

Posted: Tue Jan 05, 2010 1:32 am

DLL shown below cannot be loaded in sandbox.

dll.c:

Code:

// nothing to do, but typical crt based DLL
#include<windows.h>
BOOL WINAPI DllMain (HANDLE hInst, ULONG ul_reason_for_call, LPVOID lpReserved){
return TRUE;
}

exe.c:

Code:

#include<windows.h>
#include<stdio.h>

int main( int argc, char *argv[], char *envp[] ){
HINSTANCE h=LoadLibrary("dll.dll");
if(h){
printf("loaded: %x\n",h);
}
}

mk.cmd:

Code:

cl /MD /LD dll.c /link /fixed /base:0x800000
cl /MD exe.c

Posted: Wed Jan 06, 2010 12:03 pm

I see these messages in windbg:

Code:

LDR: LdrRelocateImageWithBias() failed 0xc0000018
LDR: OldBase : 00800000
LDR: NewBase : 003F0000
LDR: Diff : 0x7c90d6dc0012f768
LDR: NextOffset : 00000000
LDR: *NextOffset : 0x0
LDR: SizeOfBlock : 0x3f0000

I am not sure why, but it looks like under Sandboxie, the 0x800000 address is not available, although it also doesn't look like it's allocated.

But why would you specify /FIXED ?

Posted: Thu Mar 10, 2011 2:37 pm

Update. I had a chance to look into this again while I was looking into a related issue. It appears the address 0x800000 becomes unavailable when Sandboxie loads the GDI32 DLL into the process. This is just a minor informational update.