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memscan firstScan returns one address and its 0x0

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matrix_smq
How do I cheat?

Reputation: 0

Joined: 28 Oct 2021
Posts: 2

Posted: Fri Sep 01, 2023 7:45 am Post subject: memscan firstScan returns one address and its 0x0

Hello,
I've been looking for ways to search for a pointer
(The neededPointer is a Dictionary struct, and the lower pointers keep changing when resizing the Dict.)

Code:

[[[neededPointer+10]+18]+30] = myValue

but was mostly unsuccessful ( tried custom value type and some lua ).

My current try is with Memscan.firstScan to find and check all addresses that would match my constraint and crossmatch until I find the neededPointer.
I've already done this manually and it works like a charm, but in LUA, it's just not working...

(If anyone has any idea on how to make this simpler, I'm all eyes and ears.)

So, I easily got the address that holds myValue

address-30 is the first baseAddress.

when I try to scan for the baseAddress, it returns an table of 1, that contains 00000000

my code looks like this:

Code:

function callScan (value, varType)
local memScan = createMemScan()
memScan.firstScan(soExactValue,
varType,
rtRounded,
value,
'',
'0',
'00007fffffffffff',
"+W-C" ,
fsmAligned,
"4",
false,
false,
false,
false
);
memScan.waitTillDone()

local foundlist = createFoundList(memScan)
foundlist.initialize()

local output = {}
for i=1, foundlist.Count do
table.insert(output, foundlist.Address[i])
end

foundlist.deinitialize();
foundlist.destroy()

memScan.destroy()

foundlist = nil
memScan = nil

return output
end

callSign(0x1CA80, vtWord) -- returns many results

callSign(0xA171CA80, vtDword) -- returns {'00000000'}

callSign(0x1ECA171CA80, vtQword) -- returns {'00000000'}

Am I crazy? The function works fine when using it to find smaller integers

(Windows 10 / CE 7.5)

ParkourPenguin
I post too much

Reputation: 152

Joined: 06 Jul 2014
Posts: 4702

Posted: Fri Sep 01, 2023 9:48 am Post subject:

matrix_smq wrote:

Code:

for i=1, foundlist.Count do
table.insert(output, foundlist.Address[i])
end

The foundlist is a pascal object, not a Lua object. Indexing starts from 0: i.e. `for i = 0, foundlist.Count - 1 do ... end`.
It's tough to know which things start from 0 (pascal thing) and which start from 1 (lua arrays). Generally speaking, if the documentation mentions something about a byte array (e.g. readBytes, byteTableToX), it's usually a Lua array; if it's an index into a class object (e.g. address list, memory records, string list, etc.), it's usually a pascal thing.

I'd guess you got 0 due to the undefined behaviour of a buffer overflow.
_________________

I don't know where I'm going, but I'll figure it out when I get there.

matrix_smq
How do I cheat?

Reputation: 0

Joined: 28 Oct 2021
Posts: 2

Posted: Fri Sep 01, 2023 11:09 am Post subject:

ParkourPenguin wrote:

matrix_smq wrote:

Code:

for i=1, foundlist.Count do
table.insert(output, foundlist.Address[i])
end

This is actually interesting, I wonder how at least 3 scans ended up in the right memory location and the next ended up with the same results regardless of game/CE restarts. That's actually amazing.
Gotta love buffer overflows.

I've set it to start from 0 and it worked, thank you for the clarification. Maybe darkbyte will consider adding this info to the wiki/celua.txt

Dark Byte
Site Admin

Reputation: 470

Joined: 09 May 2003
Posts: 25791
Location: The netherlands

Posted: Sun Sep 03, 2023 12:09 am Post subject:

i'll add it to the manual. And it's not a buffer overflow, it's caught and just returns 0 as errorcode, and then lua converts that into the string '00000000' _________________ Do not ask me about online cheats. I don't know any and wont help finding them. Like my help? Join me on Patreon so i can keep helping

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