From: Julie DeWandel <jdewand@redhat.com>

A problem exists where a 32-bit application can have a huge bss, one that
is so large that an overflow of the TASK_SIZE happens.  But in this case,
the overflow is not detected in load_elf_binary().  Instead, because
arithmetic is being done using 32-bit containers, a truncation occurs and
the program gets loaded when it shouldn't have been.  Subsequent execution
yields unpredictable results.

The attached patch fixes this problem by checking for the overflow
condition and sending a SIGKILL to the application if the overflow is
detected.  This problem can in theory exist when loading the elf
interpreter as well, so a similar check was added there.