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Relax restriction on the segment in NtSetLdtEntries(). Look into diff for details. Thanks to Myria for providing information.

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There were no reasons found which can proof that this change could lead to security issues.

svn path=/trunk/; revision=23509
This commit is contained in:
Aleksey Bragin 2006-08-06 22:02:02 +00:00
parent 4a57b7984a
commit f792bc36a0
1 changed files with 14 additions and 2 deletions
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16
reactos/ntoskrnl/ke/i386/ldt.c
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@ -58,8 +58,20 @@ BOOL PspIsDescriptorValid(PLDT_ENTRY ldt_entry)
SegLimit=(SegLimit << 12) | 0xfff;
}
return ((Base + SegLimit > (ULONG) MmHighestUserAddress) ||
(Base > Base+SegLimit) ? FALSE : TRUE);
if ((Base + SegLimit > (ULONG_PTR) MmHighestUserAddress) ||
(Base > Base+SegLimit))
{
DPRINT1("WARNING: Windows would mark this descriptor invalid!");
}
/*
Certain "DOS32" programs expect to be able to create DPMI selectors
that wrap the address space. Windows NT does not allow user-created
selectors to reach into kernel memory. However, there is no security
risk in allowing it; the page table will prevent access anyway.
*/
return (/*(Base + SegLimit > (ULONG_PTR) MmHighestUserAddress) ||
(Base > Base+SegLimit) ? FALSE : TRUE*/ TRUE);
}
NTSTATUS STDCALL