fix potential out-of-bounds reads

readlink(3) does not nul-terminate the result it sticks
into the supplied buffer. Consequently, the code

  rc = readlink(path, buf, sizeof(buf));

does not necessarily produce a C string.

The code in rc_find_pid() produces some C strings this way
and passes them to strlen() and strcmp(), which can lead
to an out-of-bounds read.

In this case, since the code already takes care to
zero-initialize the buffers before passing them
to readlink(3), only allow sizeof(buf)-1 bytes to
be returned.

(While fixing this issue, I fixed two other locations that
used the same problematic pattern.)

This fixes #270.

0 files changed, 0 insertions, 0 deletions