Reputation: 203
I know that in 32-bit architecture the kernel mode virtual memory is mapped between 0x80000000
and 0xFFFFFFFF
.
It contains some structures as EPROCESS
, ETHREAD
... etc and also the page directories and tables for the current process.
While trying to fetch the virtual address of a certain function is ntoskrnl let's say "nt!NtReadFile" I find that's it's mapped in the kernel virtual address 0x89421130
for example.
I tried to patch some nops after the RET
with a random instruction and when switching to another process context I found that the instruction I put is still there.
Does that mean that virtual memory where Ntoskrnl is loaded stays unchanged in every process virtual address space ?
Thanks.
Upvotes: 2
Views: 1148
Reputation: 20174
Does that mean that virtual memory where Ntoskrnl is loaded stays unchanged in every process virtual address space?
Yes. There is one copy of the kernel in memory on a running Windows system, and the exact same kernel address space (i.e. 0x80000000-0xFFFFFFFF
on 32-bit) is mapped into every process.
Upvotes: 3