LIEF LIEF 0.10.1 : 04_ELF_hooking broken - cos function does not exist in output lib.so.6 file

LIEF 0.10.1 : 04_ELF_hooking broken - cos function does not exist in output lib.so.6 file

Open pdreiter opened this issue 5 years ago • 2 comments

Describe the bug Cross-referenced from tutorial issue 4 When running the 04_ELF_hooking example, make run, I get a SegFault.

make run
unset LD_LIBRARY_PATH
./do_math.bin 2
cos(2) = -0.416147
python3 insert_hook.py
Hook inserted at VA: 0x38d000
Change cos!34b70 -> cos!38d0d0
LD_LIBRARY_PATH=. ./do_math.bin 2
Segmentation fault (core dumped)
make: *** [Makefile:17: run] Error 139

Looking more closely at the generated so file, the hook function code does not exist in the output ./lib.so.6 file:

%> nm -gD ./libm.so.6 | egrep -w 'cos'
000000000038d0d0 i cos

%> gdb -batch -ex 'file ./libm.so.6' -ex 'disassemble cos'
warning: Loadable section ".note.gnu.build-id" outside of ELF segments
warning: Loadable section ".note.ABI-tag" outside of ELF segments
No function contains specified address.

python3.6
LIEF 0.10.1
Ubuntu 18.10
gcc 8.3.0

To Reproduce Steps to reproduce the behavior:

git clone https://github.com/lief-project/tutorials.git
cd tutorials/04_ELF_hooking
make all
make run

I had to make a few minor changes to get baseline to work:

changed the Makefile to invoke python3
change insert_hook.py to point to my system's libm.so.6
changed insert_hook.py to print(f"Change...") line to use .format with parameters, rather than inline

Expected behavior I expected that the cos function would exist in the ./libm.so.6 file at the offset specified by the example.

Environment (please complete the following information):