readelf: Use unsigned loop variables in handle_verneed and handle_verdef 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. Signed-off-by: Mark Wielaard <[email protected]>