Dont allow SetSelectorBase to change into an kernel region
Uwe Bonnes
bon at elektron.ikp.physik.tu-darmstadt.de
Wed Aug 1 12:44:54 CDT 2001
>>>>> "Uwe" == Uwe Bonnes <bon at elektron.ikp.physik.tu-darmstadt.de> writes:
Uwe> Hallo, galep3 crashes with following sequence: 096c7b38:Call
Uwe> KERNEL.189: SETSELECTORLIMIT(0x0d87,0x0000045f) ret=02e7:6fb5
Uwe> ds=099f 096c7b38:Ret KERNEL.189: SETSELECTORLIMIT() retval=0x0d87
Uwe> ret=02e7:6fb5 ds=099f 096c7b38:Call KERNEL.187:
Uwe> SETSELECTORBASE(0x0d87,0xc02924e0) ret=02e7:6fc1 ds=099f
Uwe> 096c7b38:Ret KERNEL.187: SETSELECTORBASE() retval=0x0d87
Uwe> ret=02e7:6fc1 ds=099f ... Unhandled exception: page fault on read
Uwe> access to 0xc0292545
Uwe> Obviously the application trys to reach some kernel memory.
Uwe> If I only allow to set the selector base when (selector base +
Uwe> selector limit) is smaller than 0x8000000, the application goes on
Uwe> and lets me read an eprom plugged into the Galep3 Programmer. Is
Uwe> the appended fix a right acceptable?
Obviously not modifying the base in that case lets me save and exit too
Index: wine/memory/selector.c
===================================================================
RCS file: /home/wine/wine/memory/selector.c,v
retrieving revision 1.39
diff -u -r1.39 selector.c
--- wine/memory/selector.c 19 Jul 2001 00:39:10 -0000 1.39
+++ wine/memory/selector.c 1 Aug 2001 17:42:53 -0000
@@ -326,8 +326,15 @@
{
LDT_ENTRY entry;
wine_ldt_get_entry( sel, &entry );
- wine_ldt_set_base( &entry, DOSMEM_MapDosToLinear(base) );
- wine_ldt_set_entry( sel, &entry );
+ if ((base + wine_ldt_copy.limit[sel >> __AHSHIFT]) > 0x8000000)
+ {
+ FIXME("Illegal region base %lx limit %lx\n", base,wine_ldt_copy.limit[sel >> __AHSHIFT]);
+ }
+ else
+ {
+ wine_ldt_set_base( &entry, DOSMEM_MapDosToLinear(base) );
+ wine_ldt_set_entry( sel, &entry );
+ }
return sel;
}
--
Uwe Bonnes bon at elektron.ikp.physik.tu-darmstadt.de
Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------
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