[bug-diffutils] bug#31935: bug#31935: 2 crashes in diffutills commit version 576645c

[Jim Meyering]

On Fri, Jun 22, 2018 at 7:49 AM Hongxu Chen <address@hidden> wrote:
>     We found with our fuzzer 2 crashes on diffutils version 576645c: one is a 
> heap-buffer-overflow at util.c:1249, another is an invalid read resulting 
> from `output_1_line' at util.c:1274.
>     The executing command is: `./diff -a --strip-trailing-cr $file add.wasm` 
> where $file is the poc file (I attached them as  *.input.txt); "add.wasm" is 
> also attached however it seems that content of the comparison file is not 
> important.

Thank you for fuzz-testing diffutils.
FYI, here is a reproducer for the limit[-1]-related UMR bugs:

  valgrind src/diff -a --strip-trailing-cr <(printf '\r') <(echo a)

I've attached a patch:

diffutils-UMR.diff
Description: Binary data