Hi, The following patches are mostly focused on ensuring AT_RANDOM array is aligned on 16bytes boundary, and while being located at a pseudo-random offset on stack (at most 256 bytes).
This patchset also insert a random sized (at most 15 bytes) padding between AT_RANDOM and AT_PLATFORM and/or AT_BASE_PLATFORM. It also insert a random sized padding (at most 256 bytes) between those data and the arrays passed to userspace (argv[] + environ[] + auxv[]) as defined by ABI. Adding random padding around AT_RANDOM, AT_PLATFORM, AT_BASE_PLATEFORM should be viewed as an exercise of cargo-cult security as I'm not aware of any attack that can be prevented with this mechanism in place. Regards. Yann Droneaud (3): binfmt/elf: use functions for stack manipulation binfmt/elf: align AT_RANDOM array binfmt/elf: randomize padding between ELF interp info fs/binfmt_elf.c | 110 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 86 insertions(+), 24 deletions(-) -- 2.21.0
