This patch series adds proper validation of an object in ksize() --
ksize() has been unconditionally unpoisoning the entire memory region
associated with an allocation. This can lead to various undetected bugs.
To correctly address this for all allocators, and a requirement that we
still need access to an unchecked ksize(), we introduce __ksize(), and
then refactor the common logic in ksize() to slab_common.c.
Furthermore, we introduce __kasan_check_{read,write}, which can be used
even if KASAN is disabled in a compilation unit (as is the case for
slab_common.c). See inline comment for why __kasan_check_read() is
chosen to check validity of an object inside ksize().
Previous version:
http://lkml.kernel.org/r/20190624110532.41065-1-elver@xxxxxxxxxx
v2:
* Complete rewrite of patch, refactoring ksize() and relying on
kasan_check_read for validation.
Marco Elver (4):
mm/kasan: Introduce __kasan_check_{read,write}
lib/test_kasan: Add test for double-kzfree detection
mm/slab: Refactor common ksize KASAN logic into slab_common.c
mm/kasan: Add object validation in ksize()
include/linux/kasan-checks.h | 35 ++++++++++++++++++++++------
include/linux/kasan.h | 7 ++++--
include/linux/slab.h | 1 +
lib/test_kasan.c | 17 ++++++++++++++
mm/kasan/common.c | 14 +++++------
mm/kasan/generic.c | 13 ++++++-----
mm/kasan/kasan.h | 10 +++++++-
mm/kasan/tags.c | 12 ++++++----
mm/slab.c | 28 +++++-----------------
mm/slab_common.c | 45 ++++++++++++++++++++++++++++++++++++
mm/slob.c | 4 ++--
mm/slub.c | 14 ++---------
12 files changed, 135 insertions(+), 65 deletions(-)
--
2.22.0.410.gd8fdbe21b5-goog
