Linux distributions that have not patched their long-term kernels with
https://git.kernel.org/linus/a87938b2e246b81b4fb713edb371a9fa3c5c3c86
(committed on April 14, 2015). This kernel vulnerability was fixed in April
2015 by commit a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (backported to
Linux 3.10.77 in May 2015), but it was not recognized as a security threat.
With CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE enabled, and a normal top-down
address allocation strategy, load_elf_binary() will attempt to map a PIE
binary into an address range immediately below mm->mmap_base.
Unfortunately, load_elf_ binary() does not take account of the need to
allocate sufficient space for the entire binary which means that, while the
first PT_LOAD segment is mapped below mm->mmap_base, the subsequent PT_LOAD
segment(s) end up being mapped above mm->mmap_base into the are that is
supposed to be the "gap" between the stack and the binary.

sbeattie

fixed upstream in 4.1, so xenial and newer had it went through stable, trusty had it in 3.13.0-56.93, precise in 3.2.0-91.129, vivid in 3.19.0-19.19