Questions tagged [kernel]

Mostly used for explaining core components of an operating system.

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12
votes
3answers
735 views

Trying to understand this construct in Dbgv.sys driver for DbgView tool

I'm trying to reverse the Dbgv.sys (x86 kernel driver) for the DbgView tool. It has this sub_10D4A function that is called almost at the beginning of the driver's DriverEntry function. It goes as such:...
7
votes
2answers
936 views

Getting the current process in Windows

While reading Practical Reverse Engineering by Bruce Dang, I came across the following. Am I correct in my assumption that the procedures return a pointer to the current thread and current process ...
4
votes
1answer
263 views

ntoskrnl checksum mismatch

I had hex-edited windows kernel file c:\windows\system32\ntoskrnl.exe to fix some assembly bytes in the way i need it. System wont boot because of STATUS_IMAGE_CHECKSUM_MISMATCH error (0xC0000221; ...
4
votes
2answers
447 views

Kernel debug - internet explorer in kernelmode?

My setup: Windows 10 with windbg and target machine is Windows 7 N SP1. I'm debugging via com (i know it's slow ;). So I get the process list with !process, one active process is Internet Explorer: ...
3
votes
2answers
154 views

Windows - syscalls being called in a strange way?

I've been reading about the way syscalls are called in windows. The general theme in all the articles I read is: 64bit- called inside ntdll 32bit- from ntdll jumping to KiFastSystemcall but when I ...
3
votes
2answers
1k views

Slow kernel dbg with VirtualBox and WinDBG

I am trying to do windows kernel debugging with VirtualBox and WinDBG. But every time I hit a breakpoint the virtual machine CPU usage skyrockets and the CPU registers do not show up in WinDBG. Am I ...
3
votes
1answer
450 views

How to use windbg to view assembly code of kernel function?

I am using windbg for local kernel debugging. I want to view the disassembly of a kernel function (eg. AuxKlibQueryModuleInformation). I am not familiar with kernel debugging. Please help me do this.
3
votes
1answer
230 views

Questions about enabling special pool on win32k

So there is win32k.sys, win32kbase.sys, win32kfull.sys in Windows 10 Does verifier /driver win32k.sys /flags 0x1 enable special pool on all three drivers? (win32k.sys is kinda like stub to other ...
2
votes
2answers
1k views

How does QPST work and how can I make an app like it?

How does Qualcomm's QPST work? Or what protocol/commands does QPST use? As I wanted to develop an app like it, I searched for AT commands. But I can't find out any AT commands that allows me access(...
2
votes
1answer
127 views

Windows x86 compability on x64 operating system

I know some about wow64 system, in x64 windows version, and i looked up into this wow64* dlls, to see how the actual syscall transition happen, but something i can't find, and this is probably done by ...
2
votes
2answers
844 views

windbg - Why does the GS register resolve to offset 0x0?

I'm trying to understand how to resolve segment addressing (specifically the GS register in X64). My toy program: int main() { unsigned long long x; __debugbreak(); x = __readgsqword(...
2
votes
1answer
2k views

extract zImage from MS-DOS executable

I have an aarch64 kernel image with the following magic number: root@localhost:/# cat msImage|xxd -l4 00000000: 4d5a 0091 MZ.. root@localhost:/# file msImage ...
2
votes
1answer
64 views

WinDBG doesn't resolve function names when debugging kernel module

I am debugging a kernel driver. When I set a breakpoint with WinDBG in one of its functions but it doesn't complete the function names while on IDA it shows the names (statically). Here is a picture ...
2
votes
1answer
91 views

Linux keyboard driver windows reverse engineering

I have toshiba portege x30-f laptop with Fn keys not working under linux. I've read some articles about usb drivers reverse engineering, but the keyboard connected not via usb. As I can understand it ...
2
votes
1answer
72 views

Get return address from syscall

I'm debugging some 32-bit process using windbg kernel debugger. This process calls some syscalls, so I set few breakpoints at kernel functions like nt!NtQuerySystemInformation. So after breakpoint hit,...
2
votes
0answers
391 views

IDA Pro macOS kernel debugging and lldb support

I'm trying to revers some kexts on macOS and I can't find a way to achieve the same level of debugging you can do on Windows kernel with IDA and WinDBG. Is there a way to add support for lldb? Or can ...
2
votes
1answer
897 views

How to find Xref to strings in proprietary binaries?

When I try to disassemble proprietary ARM binaries (no symbol), like Android phone's boot loaders, I find there are a bunch of strings that do not have any "Xrefs to" in IDA Pro. The image has ...
2
votes
0answers
1k views

Using QEMU to boot arm uImage kernel

I'm currently trying to reverse engineer the firmware for the Swann DVR16-4500 security camera system. I successfully extracted the cramfs filesystem and now I have the following files inside the ...
1
vote
1answer
308 views

Where can you find the name of a driver causing a kernel mode crash?

I am in an interesting situation. I have very limited Windows kernel experience, so I just don't know what data structure to look for in order to find what I need to know. There is a driver that is ...
1
vote
1answer
569 views

windbg - What is the relation between the VAD (!vad), the PTEs (!pte), and loaded modules and sections (lm and !dh)?

[cross-posted (but closed the original) from https://stackoverflow.com/q/55438806/254959] I'm trying to gain a better understanding on Windows process memory, and have some gaps with regards to the ...
1
vote
1answer
2k views

Rebuilding a symbol table for a firmware binary

I am trying to reverse engineer the Linksys WAG120N router firmware. I've been able to unpack it and extract the bootloader, kernel and filesystem. The kernel is MIPS big endian. I loaded the kernel ...
1
vote
1answer
361 views

How to identify which iOS kernelcache is installed?

I've an iPhone7 running iOS11.3 (15E216). The ipsw for this build version contains two separate kernelcache files named kernelcache.release.iphone9 and kernelcache.release.iphone10. Neither file is an ...
1
vote
0answers
55 views

Windows or Linux x86 Scheduler instructions

I want to understand how multi process scheduler works on x86 CPU with Linux or Windows kernels. I have read there is a kind of "timer" inside CPU. This timer gives "time slices" to each process. ...
1
vote
1answer
309 views

Analyzing Windows kernel driver

I'm trying to analyze some Windows kernel driver. What I want to achieve is full execution trace, from driver entry to end point. Driver is heavily virtualized and contains multiple anti-debugging ...
1
vote
0answers
284 views

Calling undocumented kernel functions directly (xxxSendInput and xxxMouseEventDirect)

In the core my question is about how to reverse engineer undocumented functions. I want to call the function "xxxMouseEventDirect" (located in win32kfull.sys). I have already been able to collect some ...
1
vote
1answer
67 views

HighWaterNumberOfObjects/Handles meaning?

I've been looking at some kernel debugging and came to see this: 0: kd> dt nt!_OBJECT_TYPE ffffd0851aad6c90 +0x000 TypeList : _LIST_ENTRY [ 0xffffd085`1aad6c90 - 0xffffd085`1aad6c90 ] ...
0
votes
2answers
559 views

Is reverse engineering possible for old windows kernels? [closed]

I'm interesteing, why someone not reverse engineer old windows 3.1? In theory, win 3.1 have no kernel(because kernel is dos), it's simply window manager(such as x window on unix), so why i can't ...
0
votes
1answer
452 views

Remote debugging using IDA, connecting to windbg server (kernel mode)

I do kernel debugging by using a virtual com port. One machine (host) is debugging the other machine. I have a remote machine that has IDA, and I wish to connect to the debugging session in the host ...
0
votes
1answer
160 views

Detecting user<->kernel transitions with hypervisor

Is it possible to use a hypervisor to trap all ring0<->ring3 transitions (both 0->3 and 3->0)?
0
votes
1answer
1k views

Windows XP kernel debugging

I'm trying to debug Windows XP's kernel with KD but every time I start the debugger,it seem to crash. Setup Windows 10 (host machine,running kd) Windows XP x86 SP3 VM (being debugged) I configured ...
0
votes
1answer
40 views

How to resolve major function numbers to their name while reversing windows drivers?

I'm reversing some windows drivers, and IDA never converts numbers to their corresponding major function name like IRP_MJ_CREATE = 0x00, how can i force this? is there anyway i can convert a number to ...
0
votes
3answers
48 views

How to find the address (offset) of specific driver function

I am reversing Capcom driver and in IDA I have this list of functions: I want to set breakpoint on the function sub_10590 but I don't know what is the address of this function when I am doing live ...
0
votes
0answers
31 views

Is there an event log to check when WinDbg kernel debugger fails to attach on OS load?

I'm using the latest WinDbg (Preview) to do kernel debugging on a Windows 10 client (v 1909) via a network connection in a VM. And I'm wondering if there's a log that the kernel debugger maintains? I ...
0
votes
1answer
78 views

how could i follow a system call from a dll -> kernel driver syscall

basically i would like to follow (system calls / internal calls) that basically lands in the kernel i would like for example to debug a specific dll ex : ntdll.dll and follow it to (NtXXX) function ...
0
votes
0answers
47 views

How large are privileges of linux kernel module?

I know that kernel modules are practically part of the kernel since it gets loaded inside it. But I am not sure if it really gets all privileges the system has. Can it read/write code inside the ...