The exploit is quite interesting. Initially I didn't believe there could be a problem -- after all, we have the source of "su" so who cares if we can see a cor

The exploit is quite interesting. Initially I didn't believe there could be a problem -- after all, we have the source of "su" so who cares if we can see a coredump from it? However the exploit is that "su" reads normally hidden files like /etc/shadow into memory (or more likely PAM does) thus exposing the contents of these files like password hashes to the non-root user. I wonder if it would be generally better for su/PAM to mark this data as non-dumpable (MADV_DONTDUMP), just for defence in depth. You could also imagine coredumps being uploaded in bug reports, unintentionally revealing sensitive data.