Increase mmap_base by the worst-case brk randomization so that the stack and heap remain apart.
In Linux 4.13 a change was committed that special cased the kernel ELF loader when the loader is invoked directly (eab09532d400; binfmt_elf: use ELF_ET_DYN_BASE only for PIE). Generally, the loader isn’t invoked directly and this issue is limited to cases where it is, (e.g to set a non-inheritable LD_LIBRARY_PATH, testing new versions of the loader). In those rare cases, the loader doesn't take into account the amount of brk randomization that will be applied by arch_randomize_brk(). This can lead to the stack and heap being arbitrarily close to each other. Ali Saidi (2): arm64/mmap: handle worst-case heap randomization in mmap_base x86/mmap: handle worst-case heap randomization in mmap_base arch/arm64/mm/mmap.c | 8 ++++++++ arch/x86/mm/mmap.c | 4 ++++ 2 files changed, 12 insertions(+) -- 2.15.3.AMZN
