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fixed possible paramblock memory overwrite in EXE_Load

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@244
This commit is contained in:
Ulf Wohlers 2002-08-29 12:36:31 +00:00
parent 80ac7ce34a
commit 0e36af0899
1 changed files with 10 additions and 5 deletions
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15
src/dos/dos_execute.cpp
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@ -297,7 +297,7 @@ static bool COM_Load(char * name,ParamBlock * block,Bit8u flag) {
}
static bool EXE_Load(char * name,ParamBlock * block,Bit8u flag) {
static bool EXE_Load(char * name,ParamBlock* _block,Bit8u flag) {
EXE_Header header;
Bit16u fhandle;Bit32u i;
@ -305,12 +305,17 @@ static bool EXE_Load(char * name,ParamBlock * block,Bit8u flag) {
Bit16u envseg,pspseg,exeseg;
Bit32u imagesize,headersize;
// During loading process, th param-block-mem might be overwritten (HostPt!) and
// therefore change the relocation address, so save these values.
ParamBlock block;
memcpy(&block,_block,sizeof(ParamBlock));
PSP * callpsp=(PSP *)HostMake(dos.psp,0);
if (!DOS_OpenFile(name,OPEN_READ,&fhandle)) return false;
if (flag!=OVERLAY) {
/* Allocate a new Environment */
envseg=block->exec.envseg;
envseg=block.exec.envseg;
if (!MakeEnv(name,&envseg)) return false;
};
@ -345,11 +350,11 @@ static bool EXE_Load(char * name,ParamBlock * block,Bit8u flag) {
return false;
}
SetupPSP(pspseg,size,envseg);
SetupCMDLine(pspseg,block);
SetupCMDLine(pspseg,&block);
exeseg=pspseg+16;
} else {
/* For OVERLAY */
exeseg=block->overlay.loadseg;
exeseg=block.overlay.loadseg;
}
/* Load the image in 32k blocks */
DOS_SeekFile(fhandle,&headersize,0);
@ -384,7 +389,7 @@ static bool EXE_Load(char * name,ParamBlock * block,Bit8u flag) {
PhysPt address=Real2Phys(RealMake(RealSeg(reloc)+exeseg,RealOff(reloc)));
Bit16u change=mem_readw(address);
if (flag==OVERLAY) {
change+=block->overlay.relocation;
change+=block.overlay.relocation;
} else {
change+=exeseg;
};