[PATCH] readelf: Use unsigned loop variables in handle_verneed and handle_verdef

[Mark Wielaard]

On Wed, 2024-02-21 at 22:19 +0100, Mark Wielaard wrote:
> Prevent signed underflow by changing loop variables to unsigned and
> doing count checks before decrementing. This isn't really a bug, but
> prevents UB detected by ubsan on fuzzed input. The bad (fuzzed) input
> data does get detected anyway.
> 
> 	* src/readelf.c (handle_verneed): Use unsigned cnt, cnt2.
> 	(handle_verdef): Likewise.

Pushed after a quick chat with Aaron on irc.