On Wed, Jun 26, 2019 at 2:19 PM Alexander Potapenko <glider@xxxxxxxxxx> wrote: > > Provide init_on_alloc and init_on_free boot options. akpm: May I kindly ask you to replace the two patches from this series in the -mm tree with their newer versions? > These are aimed at preventing possible information leaks and making the > control-flow bugs that depend on uninitialized values more deterministic. > > Enabling either of the options guarantees that the memory returned by the > page allocator and SL[AU]B is initialized with zeroes. > SLOB allocator isn't supported at the moment, as its emulation of kmem > caches complicates handling of SLAB_TYPESAFE_BY_RCU caches correctly. > > Enabling init_on_free also guarantees that pages and heap objects are > initialized right after they're freed, so it won't be possible to access > stale data by using a dangling pointer. > > As suggested by Michal Hocko, right now we don't let the heap users to > disable initialization for certain allocations. There's not enough > evidence that doing so can speed up real-life cases, and introducing > ways to opt-out may result in things going out of control. > > To: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > To: Christoph Lameter <cl@xxxxxxxxx> > To: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxxxx> > Cc: James Morris <jmorris@xxxxxxxxx> > Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx> > Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > Cc: Kostya Serebryany <kcc@xxxxxxxxxx> > Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > Cc: Sandeep Patil <sspatil@xxxxxxxxxxx> > Cc: Laura Abbott <labbott@xxxxxxxxxx> > Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> > Cc: Jann Horn <jannh@xxxxxxxxxx> > Cc: Mark Rutland <mark.rutland@xxxxxxx> > Cc: Marco Elver <elver@xxxxxxxxxx> > Cc: Qian Cai <cai@xxxxxx> > Cc: linux-mm@xxxxxxxxx > Cc: linux-security-module@xxxxxxxxxxxxxxx > Cc: kernel-hardening@xxxxxxxxxxxxxxxxxx > > Alexander Potapenko (2): > mm: security: introduce init_on_alloc=1 and init_on_free=1 boot > options > mm: init: report memory auto-initialization features at boot time > > .../admin-guide/kernel-parameters.txt | 9 +++ > drivers/infiniband/core/uverbs_ioctl.c | 2 +- > include/linux/mm.h | 22 ++++++ > init/main.c | 24 +++++++ > mm/dmapool.c | 4 +- > mm/page_alloc.c | 71 +++++++++++++++++-- > mm/slab.c | 16 ++++- > mm/slab.h | 19 +++++ > mm/slub.c | 43 +++++++++-- > net/core/sock.c | 2 +- > security/Kconfig.hardening | 29 +++++++++ > 12 files changed, 204 insertions(+), 19 deletions(-) > --- > v3: dropped __GFP_NO_AUTOINIT patches > v5: dropped support for SLOB allocator, handle SLAB_TYPESAFE_BY_RCU > v6: changed wording in boot-time message > v7: dropped the test_meminit.c patch (picked by Andrew Morton already), > minor wording changes > v8: fixes for interoperability with other heap debugging features > -- > 2.22.0.410.gd8fdbe21b5-goog > -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
