PTM - Paging Table Manipulation From Usermode

paging table manipulation from user-mode. operations such as getting and setting all paging table entries and values are offered. the code is aware of large pages and allows the programmer to allocate 2mb pages if needed (without going through all of the shenanigans of breaking a 2mb page down over a new PT handled by the user). Link to write up can be found here.

example

vdm::read_phys_t _read_phys = 
	[&](void* addr, void* buffer, std::size_t size) -> bool
{
	return vdm::read_phys(addr, buffer, size);
};

vdm::write_phys_t _write_phys =
	[&](void* addr, void* buffer, std::size_t size) -> bool
{
	return vdm::write_phys(addr, buffer, size);
};

vdm::vdm_ctx vdm(_read_phys, _write_phys);
nasa::mem_ctx my_proc(vdm);

const auto ntoskrnl_base =
    reinterpret_cast<void*>(
	    util::get_kmodule_base("ntoskrnl.exe"));

const auto ntoskrnl_pde = my_proc.get_pde(ntoskrnl_base);
std::printf("[+] pde.present -> %d\n", ntoskrnl_pde.second.present);
std::printf("[+] pde.pfn -> 0x%x\n", ntoskrnl_pde.second.pfn);
std::printf("[+] pde.large_page -> %d\n", ntoskrnl_pde.second.large_page);

[+] pde.present -> 1
[+] pde.pfn -> 0x10400
[+] pde.large_page -> 1
[+] press any key to close...

table entry manipulation

• get/set pml4e's
• get/set pdpte's
• get/set pde's
• get/set pte's

table manipulation

• copy table
• make self referencing table.

virtual memory

• convert virtual addresses to physical addresses
• get table entries for a given address
• change table entries for a given address

credit

• buck - inspiration for most of this.
• Ch40zz - helping me connect the dots.