ELF binary corrupted after adding instruction in non-executable section

Question

I've been messing around a little with Radare2 trying to master binary exploitation and patching.
I added a couple of assembly instructions to an x86 elf binary in a non-executable section of the file, precisely the section LOAD1 I spotted after listing the available sections of the executable :

 S=
00* 0x08048000 |#################################-----------------------------------------------| 0x0804868c  1.6K mr-x  LOAD0
01  0x08049f0c |---------------------------------------------------------------------------#####| 0x0804a028   280 mrw-  LOAD1
=>  0x080483d0 |--------------------------------------------------------------------------------| 0x080483cf

Then when I tried to execute the binary I got the following error :

Inconsistency detected by ld.so: dl-version.c: 205: _dl_check_map_versions: Assertion `needed != NULL' failed!

I think the instructions types I added are not relevant in this matter as the issue arises with mov instructions as well as with simple jmp.

From what I know, the linking step had been performed at the compilation/linking of the original source code, so how does it come that ld is involved here ?

What exactly causes the linker inconsistency triggering the above error ?

Answer 1

Note that no section information is provided in your question. LOAD0 and LOAD1 refer to loadable segments. Refer to the SysV ABI for more details.

From what I know, the linking step had been performed at the compilation/linking of the original source code, so how does it come that ld is involved here ?

The link editor ld is not involved here; rather, the dynamic linker/loader ld.so is.

What exactly causes the linker inconsistency triggering the above error ?

Run LD_DEBUG=symbols,bindings or LD_DEBUG=all.

See https://stackoverflow.com/questions/22564780/debugging-ld-inconsistency-detected-by-ld-so